June 19, 2021
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A delicious and bright rainbow cake with vanilla buttercream frosting, a pink drip and sprinkles!
Oh hellooo most requested recipe OF ALL TIME. I am not even joking, this recipe has been requested over and over again and I am ~finally~ posting it on to my blog! It’s taken a fair old time as I wanted to get it right!
I love all things cake, we all know this, but a rainbow cake is something else. The absolutely insanely bright colours, the sweet taste, and all things cute take it to a different level entirely! It is just glorious.
So… I will say from the beginning that this recipe uses lots and lots of ingredients, and it is a humongous cake! Like, its 6 layers of cake, and all the buttercream in-between the layers, and all the decor on top!
And I will also say from the beginning… YES I KNOW THE RAINBOW HAS SEVEN COLOURS. This cake, is only six. When baking this cake, I just find making 6 colours so much easier, and you can see the obvious differences. I am not bothered about the seventh!
Red, orange, yellow, green, blue and purple… the main colours you need in your life. I did slightly compensate for the lack of seven colours by adding in a pink drip on the outside but we will get to that later.
For this cake, I did make probably the biggest one tier cake ever. It’s about 8-9” in height, and uses so many ingredients. Because it is a six layer cake I decided to make it in two batches. So three layers at a time, so therefore you still only need three tins!
I made the cake a 600g mix, so that it’s super easy to split into two batches. The best way is to weigh 5-6 medium eggs, and get as close to 300g as you can, for example 312g, and then match the butter, sugar and flour to that weight.
Then, you mix it all together like normal, and then split into three bowls. It doesn’t matter which colours you do first, but I did red, orange, and yellow together, and then green, blue and purple.
The oven temperature is a bit lower than normal, as I don’t want the sponges to brown too much. This also comes somewhat from the brands of colours that you use! Red food colouring, orange food colouring, yellow food colouring, green food colouring, blue food colouring and purple food colouring. for the sponge mixtures!
Once my sponges are baked, I leave them to cool completely and freeze them wrapped in clingfilm over night so that they are easier to decorate the next day – but this bit is completely optional of course!!
For the buttercream, you do use 750g unsalted butter and 1500g icing sugar, which technically is a little obscene but the amount of servings from this cake is huge so please don’t be a negative Nelly about the sugar content!
I make my buttercream like normal by beating room temperature unsalted butter on its own for several minutes to make it really loose and supple, and then I gradually add in the icing sugar! I make sure to beat this for quite a long time.
White food colouring
You can do several methods to get whiter buttercream, by beating the butter on its own for a lot longer, or using a smidge of purple buttercream to counter act the yellow, but I love using this white food colouring! It looks amazing on my white chocolate drip cake and I haven’t looked back since.
I add a little at a time and keep beating it very well to make sure its really white and bright to contrast against the colours of the sponge! Making the buttercream whiter is completely optional of course though.
When I am starting to decorate the cake, I dollop a few tablespoons of buttercream onto each sponge and smooth over, making sure to get the order of the colours in the sponges correct of course…!
Once you have layered each sponge you need to do a crumb coat by using as little buttercream as possible around the edges to seal in the spare crumbs from the sponges! I then chill the cake for a while to firm it up before adding another layer of buttercream on top.
I use a large metal scraper to decorate the sides of the cake, and a small angled spatula to also help cover the sponges – and its much easier and you are going to get a smoother finish using these as well!
Sprinkles and drip
Just as I have finished the buttercream I carefully press in some rainbow sprinkles to the bottom of the cake for a bit of colour and I just love the design – be warned, sprinkles will fall off at this point so beware! After this, I chill the cake again!
For the pink drip, I use white chocolate ganache with this pink food colouring added in. Its a super bright colour so you don’t need add too much and it means you get the best coloured drip ever!
Finishing touches and tips
I then pipe on the leftover buttercream and add on some more rainbow sprinkles and the best cake ever is finished! I am in love with the sponges and how bright and pretty it is – but the key point to make, YOU NEED TO USE GOOD QUALITY COLOURS.
Using supermarket colourings, will NOT work as well, or maybe at all… so please don’t waste ingredients by doing this! The colourings are 100% worth the investment as they last for so long! Any questions, leave them below in the comments and happy baking! x
- 600 g eggs (weigh eggs in shell) (about 10-12 medium eggs)
- 600* g unsalted butter
- 600* g caster sugar
- 600* g self raising flour
- 1/2 tsp red, orange, yellow, green, blue, purple food cololuring
- 750 g unsalted butter (room temp, not stork)
- 1500 g icing sugar
- 1 tsp vanilla extract
- 1-2 tsp white food colouring
- 180 g white chocolate
- 75 ml double cream
- 1/2 tsp pink food colouring
- Rainbow sprinkles
For the Cake
- Preheat your oven to 160ºC/140ºC fan and line three 8"/20cm springform tins with parchment paper and leave to the side for now.
- Weigh 5-6 medium eggs in their shells and get as close to 300g as possible (e.g. 312g)
- Then add 312g of butter and caster sugar to a bowl and beat until light and fluffy.
- Add in the eggs, and 312g of self raising flour and beat again until smooth.
- Bake the cakes in the oven for 30 minutes (or until baked - test with a skewer).
- Once baked, leave the cakes to cool in the tin for 10 minutes before removing to a wire rack to cool fully.
- (You can wrap the sponges in clingfilm once they have cooled and freeze over night to make decoratin easier but this is optional!)
- Once all of your cakes are cooled, you can make the buttercream.
- Beat the room temperature unsalted butter on its own for a few minutes to soften it and make it supple.
- Gradually add the icing sugar beating very well each time until its all mixed in.
- Keep beating and add the white food colouring and vanilla extract and beat for a few minutes.
- Using a 10" cake board, add your first sponge. I start with purple as its the bottom colour.
- Add a couple tablespoons of the buttercream on to the sponge and smooth over. Repeat this with blue sponge, then green, yellow, orange and finally red at the top.
- Using a small amount of buttercream, smooth over the sides of the cakes and fill in any gaps and create a crumb coat.
- Refrigerate or freeze the cake on the board for an hour or so to chill and firm to make the next stage of decorating easier.
- Once chilled, add on lots more buttercream around the sides of the cake with a small angled spatula, and smooth over using a large metal scraper until the sides of the cake are smooth like in the photos!
- Carefully press some of the sprinkles into the bottom of the cake using the palm of your hand to create the sprinkle effect!
- Once this has been done, refrigerate again whilst you make the drip!
- Add the white chocolate and double cream to a bowl and heat in a microwave in short 10 second bursts stiring well each time.
- Once melted and combined, add the pink food colouring and mix until smooth!
- Add the pink ganache to a piping bag and carefully cut off the end and drip down the sides of the cake. The more you push over the side of the cake with the piping bag, the further it will drip!
- Add the leftover buttercream to a piping bag with your favourite piping tip and pipe swirls of buttercream onto the top of the cake (like I have done in the photos)
- Finally sprinkle on some etra sprinkles and leave the cake to set in the fridge fully.
- In the hot weather I store the cake in the fridge until it has been portioned.
- This cake lasts 4-5+ days once made!
- The colours that you use and what order are up to you, this recipe is just how I did it! You can swap up the order or whatever you prefer!
- You should avoid supermarket colours as they are not strong enough.
- In this recipe use:
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I need to make my cake 2 days before the party. Would I be best off doing the buttercream and sprinkles the morning of the party? I’m worried the colours of the sprinkles will bleed. Or even could I just do the buttercream in advance and then the sprinkles in the morning to save time?
Hiya! It should be fine, though if you’re worried then add the sprinkles the morning of! Hope this helps! x
Hi, I made this and everything came out fine expect the pink drink it went so gloopy and almost like slime and just hasn’t set like ganache why could this be?
Hiya! This can be due to the type of food colouring used, you can try adding a tad more cream to make it more runny! Hope this helps! x
Hi Jane, I love your rainbow cake!
How tall would this cake be? As I’m looking to purchase a cake topper. Also do you have an egg-free sponge that suitable for this recipe? My daughter has food allergies
Many thanks x
Hi Jane and team, will be making this cake next month. When mixing in the colours, I;m thinking it will take a good mix to blend colours. So, is that ok? always iffy about the “don’t over mix” rule, Thanks
Hiya! Yes this should be fine, just mix until combined then leave them! Hope this helps! x
If I was going to do this as a 6 layer smaller 6 inch cake could you let me know what the ingredient ratios would be and the cooking time.
Hi Jane I’m making this for a combined birthday. However we don’t have self raising flour where we live. And there’s conflicting diy baking powder:flour ratio on Google. What’s your advice please?? Much appreciated thank you!
Hiya! For every 150g plain flour used, whisk in 2 level tsp baking powder before using. Hope this helps! Team Jane 🥰 x
Hey, I’m going to make this for my daughters first birthday. I tried clicking on the link for the white food colouring but it doesn’t work anymore, could anyone point me in the direction please? Thank you.
I too would like to be advised so following. Thanks!!
Hiya! The link should be working now. Hope this helps! x
I made this for my daughters birthday. First time making a layer cake or a rainbow cake and it came out PERFECT what an awesome recipe it tasted fab!
Hi, if I were to bake the cakes and pop them into the freezer, can I leave them for a few days before taking them out to decorate? My weekday schedule is busy therefore I was hoping to bake the cake a week before it is needed and finish the decorating almost 5 days after! Thanks!
Yes absolutely, you can freeze them for up to 3 months in total! Hope this helps x
I’m going to try making this cake for my goddaughters birthday. She’s allergic to dairy so I was going to switch out the butter for dairy free butter but I’ve noticed some of your vegan cake recipes use vegetable oil instead of butter. Is that something you would recommend for this one too?
Hiya! If you are after just a dairy free version, I would just use dairy free butter! Hope this helps! x
Hi Jane! I’ve been asked to make a gender reveal cake for my cousin and this would be perfect in shades of pink or blue so could I do just 3 layers if I half the recipe as 6 might be too many? I also have Wilton gel colours, would they suffice? Thanks in advance 🙂
Hiya! Yes that sounds great, wilton gel should be fine! Hope this helps! x
Hi Jane! I’ve been asked to do a gender reveal cake for my cousin, so wanted to do this but on a smaller scale! Could I just half the amount to do three layers and then colour appropriately? I also use Wilton gel colours, will they work as well? Thanks in advance 🙂
Yes absolutely, this should be fine! Hope they love it! x
Hello Jane, was wondering how I could make this but with only 4 layers? Nor sure om ingredients!
Could you roughly tell me how tall this cake is? I need to store/transport it in a car for a few hours and wondering if it’ll fit in my cool box! I’m worried it won’t fit!
Hiya! At a guess – id say around 7-8″. Hope this helps! x
Hi Jane! This rainbow cake looks amazing! I’m planning on making this for my friend’s daughter’s Christening for next sunday, but she’s asked for a salted caramel frosting/buttercream instead of vanilla. What would be the amounts/ingredients for salted caramel frosting/buttercream? Also, is there any way of making the frosting white or is that impossible if it’s a caramel one? Thanks! 🙂
Hiya! Take a look at my salted caramel cake recipe! Sadly you probably will not be able to achieve white. Hope this helps! x
I love your recipes so much but need help. I want to make white chocolate coating but in a colour. Is this possible and what chocolate and dye would go together that I can do this.
I tried melted white chocolate and adding a gel food dye in but it didn’t work and gone horribly wrong
I’ve heard candy melts are good please help
Hiya! Take a look at my White chocolate drip cake for the chocolate buttercream, and my ‘my favourite food colourings’ post where I link which colour works best with chocolates! Hope this helps! x
Omg omg!! Let me just say this was my first time trying to bake a cake and oh my gosh it’s literally turned out stunning!! I wish I could upload a picture because WOW
Would it be the same amounts for a 10”cake with 4 layers? What about baking time? Thank you!
Would you recommend putting cake dowels in to make the cake more sturdy and less prone to falling over?
Hiya! You can do – but this cake should be fine without also! Hope this helps! x
Hi, to remake one sponge layer? Would it be 100g of each ingredient?
Hi Jane. I love doing your recipes! Going to make this for my 5year old’s birthday, but want to use a 9 inch square tin (as just find them easier to slice up for a crowd) Would you use the same quantity and have thinner layers, and decrease the cooking time, or increase the ingredients, if so by how much?
Might be a silly question but when you freeze the sponges do you need to defrost them before assemble or can you decorate them straight from the freezer
I have made this recipe a few times and love it!
How do I convert it for a smaller 6inch cake instead of 8inch please
Hi Becky, did you find this out as I wanted to do this cake but in a 6inch time? Xx
I’ve made these sponges today ready for my daughters birthday cake at the weekend, but the sponges are only an inch deep and seem sticky on the top. Does this sound right? Or do you know where I might have gone wrong? I weighed all ingredients to match the weight of the eggs. Batch was 306g and batch 2 was 302g.
Mine have done the same! Did you find out why?
Hi Jane, I’d like to make this cake but on a small scale. Can you tell me the weights for a 6” and 7” tin? Also what would you reduce the food colouring quantities too. Thank you.
Hi, can I use a white chocolate buttercream instead to cover the cake with no drip thanks
Can I use the Wilton easy layers tins for this recipe? 🙂
Hello. Planning to make this cake for my daughters birthday. Does stork or butter work better for the sponge please? Is there a difference in the taste/texture of the cake depending which you use? Thank you in advance
I always use stork for sponges as I find it is lighter – I never use it for buttercream though!
I am looking to make this for my daughters birthday but am finding it really hard to find any sprinkles that are bright enough, could you please tell me which ones you used. Thank you !!
Please can you put a link for the sprinkles? They are so vibrant! Which is hard to find in the UK. Thank you xx
This is the cake I want to make for my girls 1st birthday!! Literally what I pictured in my head haha!
However, it doesn’t need to be so big, I’ve got 5 x 6inch cake tins… could you please help me with adjusting the ingredients x
Hi Jane can I leave this in the fridge over night unwrapped if not what can I wrap with
If you mean fully decorated, yes you can – and as long as you have a clean fridge and its correctly stored its fine!
Sorry if this is a silly question. But if freezing the night before, are you then icing the next day when the cakes are still frozen or do you take them out early to defrost and then decorate?
Thanks so much!
I just decorate from frozen! x
Hi Jane, if I decide to freeze the cakes over night in cling film, how long do I need to wait for them to defrost before I start icing and assembling the cake? Thanks! X
Hi Jane. This cake looks so amazing and I am planning on making this for my sons birthday. As there will be quite a few people at the party I am planning on using 10 inch cake pans and increasing the recipe a bit and increasing the baking times. Would this work and how long would I need to bake the layers for?
And also would it work as a 7 layer cake? I was thinking of doing a pink layer too!
Hi Sandy did you ever make this as a 10 inch as I am
looking at doing the same and wondered how much
you increased the ingredients?
I showed this cake to my 4 year old and she is desperate to have it for her birthday this year. The only issue is we are having a party that consists over about 25 children plus at least 1-2 adults per child.
If I dowel the bottom layer do you think it would work do a 2 tier stacked cake and do 2 layers of each colour sponge so the rainbow works across the entire cake.
I would really appreciate any tips.
Thank you so much
Would both cakes still be 8″? I would say it is risky as it’s going to be tall and not that wide. It may be best to just make two if so!
Thank you for the reply Jane.
I am completely open about the sizes. I can make the lower tier a larger size so I can stack the tiers. So I could do the top teir the 8” and then a large size on the bottom?
Yeah, that works! Or you can do 8″/6″ – I have my two-tier celebration cake which may help you but timings-wise, the baking times will change for different sized tins. x
If I wanted to make it a 3 layer cake instead can I just half the recipe? Would the cake still be a nice size?
For the colourings, can you also use ProJel or does only the brands listed work?
I’ve just listed the exact ones I use – some of them are progel! You can use all progel if you wanted, as they are a good brand! x
Hi Jane, ive been eyeing to use this cake for my daughter’s birthday. Can i add flavor on each layer, like strawberry for the red, melon for orange, mango for yellow etc? How much do you recommend to put on each layer? When in the steps shall i add the flavor? Thank you so much.
Yeah for sure!! And how much depends on brand – usually they advise how much on bottles of flavouring. I would add it with the colour x
Hi Jane love your recipes and this cake and how vivid the rainbow sprinkles are! Could you tell me what brand these are please? I can’t find any this vivid when I search, thanks x
Would really love to try out this recipe,but I just want to check first after mixing the butter and sugar ,do you add the eggs 1 at a time or all together ? With the flour ?
I add all the eggs in with all the flour – if I do it one by one I will always say in the method x
Hi Jane, I am planning to do this tomorrow and Saturday for Sunday’s party (to give me much time to make it), just wondering if I can use the Ruby chocolate instead of white chocolate? Will that be similar measurements or ratio? Thank you.
Hi Jane! Did you use the same 8inch cake tins that you’ve linked in previous recipes for this cake? Thank you! X
Would you ever put jam in a couple of the layers under the buttercream or is that a no no?
You can, but its a risk where the cake is so tall that it might slide about a bit if you aren’t confident! x
Hello Jane, firstly thank-you very much for sharing your recipes ❤
I am making the rainbow cake but had to look back as I thought I had something wrong. Your amounts are 600g but then it goes to half the amount lol. Just thought I would tell you in case you didn’t know xx
On the post it explains that it is because you only make half the cake at a time – so the totals are 600g roughly, but for the first half you only use 300g x
Could you please link the tins you used for the recipe? Are they the same ones linked in others such as the raspberry ripple cake? Hoping to make this in a few weeks for my boys 2nd birthday. Thank you for all your bakes, they have never failed and always taste amazing xx
Yes I did – but I also have a great blog post on all cake tins I use!! x
Hi Jane, I’m planning on making this cake for my daughter’s 2nd birthday next week. I have a couple of questions; do you trim yourself sponges before layering? And presumably it’s ok to keep sponges frozen for a few days before assembling and decorating if trying to get ahead?
Hiya! I did not trim them (other than the purple one ever so slightly as it caught) and yes you can freeze for a few days easily! x
Hi Jane, thanks so much for sharing this recipe! I’m planning to make for my daughters birthday cake in a couple of weeks but wondered if you think it would be okay to use icing (only because I have some Hey Duggee figures I’m making to put on the cake) rather than buttercream? And would I still be okay to refrigerate the cake once decorated if it’s hot with icing
Thanks so much!
I personally don’t refrigerate cakes with fondant icing on as it can make it sticky x
Do I need to trim the edges of the cakes before I crumb coat?or just leave it as it is out of oven?sorry I’m not great at the decorating part 🤣🙈
No you don’t need to x
Thanks for sharing, this cake looks amazing, perfect for a party 🙂
Hi, I am hoping to make this cake for my daughter’s birthday next week but I was wondering whether this recipe would be suitable to make into a pinata cake or are the layers too thin to cut a hole in the centre of? Thanks!
Hi! I’m hoping to make this cake for my daughters birthday next week. Could I turn this into a piñata cake or would the sponges be too thin to cut a hole in & then stack?
It would be worth chilling the sponges before cutting the hole out so they are easier to manoeuvre as they are relatively thin xx
When you say to match the ingredients eg 312g – is that
312 caster sugar
312 SR flour?
Sorry I just don’t want to make all the effort to then ruin by silly mistake!
Also I don’t bake often but am hoping to do this for my daughters birthday. Would you say this recipe is ok for beginners?
Yep exactly that. If 312g is the weight of the eggs in the shells, you match the weight with the butter sugar and flour!
I am NO baker, but I made this for my daughter’s birthday this weekend and it was SO GOOD! When she cut out the first slice there was a collective “WOW” from her friends . . . I used the exact colours as recommended and they came out so bright and fabulous, especially against the whitened buttercream. I was so worried that it wouldn’t look good because it’s my first attempt at anything like this, but it was honestly so straightforward and just took a little time.
I struggled to figure out how to press the sprinkles onto the bottom with my hand so in the end I put them on the board around the bottom of the cake then lifted them with a butter knife and pressed them on to the sides of the cake.
Thank you so much Jane for your recipes – I’m a hero to my daughter and her friends now 😉
Gorgeous cake, I made for my boys birthday, used supermarket gel and came out better than expected but not quite as vibrant, opted for blue drip. One thing I could note is make sure you leave enough time for the drip to cool before putting the buttercream on.. I didn’t and unfortunately had some melting casualties haha fixed with a chill in the fridge.
Ahh maybe your ganache was thinner than mine – that can depend on the colouring as well! x
Hello, I’m just wondering if you froze the cake before decorating or not. I’m wanting to make this for my little boys birthday next week. But can’t decide whether to freeze it once it’s been baked. As I’m terrible at decorating
Apologies In advance, because I HATE reading these kind of questions… but if you were to do it in 6 inch tins, would it be ache to hold itself up? Just thinking I’d love to make it but I’d have nowhere near enough people to eat one this big. Sorry again, I know you’re not here to make recipe adaptations, just curious if a 6 inch 6 layer cake
I would maybe use a central dowel for a 6″ one as it is less in diameter!
How long do you need to leave it after decorating frozen till you can eat it? Thanks! Love all your recipes! !
By the time you have decorated it and left it in the fridge etc etc it should be fine to eat – depends how long you freeze the sponges for as that is an optional part of the recipe.
My daughter has been asking for a rainbow cake for a while so when I saw your recipe I thought I’d give it a go! Cake turned out perfectly and the recipe was super easy to follow. My daughter loved it thank you so much for the recipe 🙂🙂
I’m new to freezing cakes. Do you recommend keeping the cake in the fridge once it’s decorated? And will the icing be ruined if the cake is defrosting? (Sorry if thats a silly question, I’m always hesitant!)
Generally I don’t keep cakes in the fridge unless there is a fresh topping – but the cake would be fine in the fridge before it’s portioned, afterwards it will dry out. And freezing of the sponges is optional as mentioned on the post, you can just chill them for a bit.
This recipe looks great! Im looking at doing a 4 layer drip cake! In a 8inch tin would this be enough for 4 layers?
This recipe is in 8″ tins already – so do you want to do less mix? I’m not sure what you mean sorry.
Is there any way to make this cake gluten free?
Always worth trying gluten free alternatives and maybe xantham gum!
Hello! When I used colouring previously in sponges I always struggle with it baking properly and it being to wet and dense. Any suggestions on how to avoid this?
Use the colours I have recommend and linked as I do not experience this!
Hi Jane! This cake looks amazing 🤩 I always seem to struggle with the drip and I wonder if it could be the type of white chocolate. Is there a type or brand that you would recommend? Thank you!
Hey, I use Callebaut chocolate for drips xx
Can’t wait to try this for my daughters birthday next week, it looks amazing!
Can I ask which food colours you used. I’ve found in the past that If you need to add quite a bit of colour it makes the cake taste nasty.
All of the exact colours I use are linked in the post and on the recipe notes! I hope you love it!! x
After taking the cakes out of the freezer how long do you leave them before decorating?
I decorate from frozen – I don’t thaw them!!
Hi, this looks amazing, I can’t see anywhere the make of the food colouring you use, could you please let me know which make you use.
They all are linked on the post, and in the notes!
I’d like to make this as a 4 tier as 6 will be too big, so I’m not sure of the ingredient measures
Which brand of food coloring do you recommend?
They all are linked on the post, and in the notes!
Hi Jane! I love your recipes! Excited to make this one for my daughter’s first birthday! Question- can I refrigerate the sponges instead of freezing it a day ahead of doing the buttercream icing? If I did freeze them how do you recommend defrosting them for decorating?
Ahh yay!! I just decorate from frozen – I don’t thaw the sponges and I find it much easier! You can refrigerate them instead though but only for an hour or two to make it easier to decorate! x
Wow this rainbow cake looks like the dream!!! Might make this for my little girls fifth birthday! What rainbow sprinkles did you use?
I got these particular ones from America so you can’t get them easily, but its worth a google!!
I made a celebration cake last week with a white chocolate drip. I turned to your recipes (as I always do) for all the elements of the cake. The drip was just white chocolate in one of your other recipes, no oil or cream added and I think you wrote it’s something to do with white being a different consistency to milk and dark. In this recipe though you do use cream. Can you tell me why? I’m trying to perfect my drip with every cake I make. Thanks!
I do various different types of drip, but I wrote that on that post because often people will just straight swap the chocolates which doesn’t work! Either method works, but this one works quite well when adding colour!