August 31, 2018
Chocolate Cake Traybake!
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Thick chocolate cake traybake, with thick chocolate frosting! Perfect for parties, or occasions, or anything!
Traybake cakes
I haven’t done too many traybake recipes in my time, if you talk about cake style traybakes. The other side, the brownies, blondies, rocky roads etc I have done almost too many to count (whether the recipes made it to the blog or not), but cake wise? Only a few. This is for any particular reason to be honest, just because I never thought they were very ‘wow’.
To be fair, I am completely wrong. I often get requests for a cake like this, and I just haven’t really got round to it until now! When I posted my carrot cake traybake in March, it was SUCH a big hit! I honestly didn’t expect it, and it was a bit of a random one to plug some days up in the run up to Easter, but I regret not posting it sooner!
Requested recipe
I thought originally “oh its just a cake that you give out at a party, if you don’t want the centrepiece cake too big”, which is actually often a thing. People create a ‘cutting cake’ if they don’t want, or can’t have the actual wedding cake for example that massive. I just didn’t realise that people like making them at home so much!
When I have asked in the past for requests of recipes, I usually get really out there ones that are almost a bit too specific for my blog, or ones that I have done, or ones that I would happily do. But quite often or not, there are ones that are just basic bakes that I have managed to have not done already, or ones that completely passed my mind like this one!
Sponge
When starting this recipe I wanted to make sure that it was going to be delicious. When you have a traybake cake, there is NO WHERE to hide. You can’t layer it up and make it look that pretty, and its so big that its awkward to try and cover up in some way. I wanted to make sure that the cake was suitably fudgey, and delicious, like the ‘traybake cakes’ that you can buy for parties in the supermarket.
You can easily do it with a straight forward Victoria sponge style sponge but I just think if you really are only leaving it as is, with some frosting on top, then I wanted it a smidge denser to make it more delicious. I ended up basing it on my chocolate fudge cake recipe, but slightly altered to fit the tin better!
Coffee and buttermilk
Because this sponge uses coffee, and buttermilk, it creates the most wonderful thick gooey sponge that everyone wants to devour. Trust me, YOU CAN’T TASTE THE COFFEE, and it just enhances the chocolate flavour so I would 100000% recommend sticking with it! Honestly, you’ll regret it if you don’t. You can use actual espresso, or instant coffee etc, but anything dissolved in 125ml of water will do.
Frosting and decoration
The Frosting for the cake is also from my chocolate fudge cake recipe, as its just personally the best chocolate frosting on the planet ever. This is optional, you could easily use just melted chocolate, or a ganache type frosting, but I really wanted a good solid frosting instead that is usually a crowd pleaser, and from the comments I have received in the past, this is the frosting to choose! You can decorate it how you want, but I just went for some sprinkles and some small chocolate bits and it’s all done! Cut up into squares and enjoy! x
Chocolate Sheet Cake!
Ingredients
Cake
- 250 g dark chocolate
- 250 g unsalted butter
- 1 tbsp instant coffee
- 125 ml boiling water
- 200 g plain flour
- 50 g cocoa powder
- 1.5 tsp baking powder
- 1/2 tsp bicarbonate of soda
- 250 g caster sugar
- 250 g light brown sugar
- 4 large eggs
- 100 ml buttermilk
Frosting
- 250 g unsalted butter (room temp)
- 500 g icing sugar
- 50 g cocoa powder
- 100-125 ml evaporated milk
- 1 tsp vanilla extract
Extras
- Sprinkles
- Chocolate curls
Instructions
For the Cake
- Preheat your oven to 160/140C Fan, and line a 9x13" tin with parchment paper.
- In a heatproof bowl, microwave the dark chocolate & butter until melted – mine takes two minutes!
- Pour the coffee granules into 125ml boiling water and mix – add the coffee to the chocolate/butter mix and stir well until smooth!
- In a separate large bowl add the plain flour, cocoa powder, baking powder, bicarbonate of soda, golden caster sugar, and light brown sugar and mix well so the ingredients are all mixed with each other well!
- Mix the eggs with the buttermilk – add the chocolate mix & the egg mix to the dry ingredients and stir together, try not to over mix it – you don't need to use an electric mixer, just use a bowl and a spatula.
- Pour the mixture into the tin and bake in the oven for 50-60 minutes (can take a little longer in some ovens) once baked leave to cool in the tin and remove afterwards, or leave for 10-15 minutes and cool on a wire rack for a softer cake.
For the Frosting
- With an electric mixer with the paddle attachment, beat the butter until its very smooth and supple (couple of minutes)
- Gradually add the icing sugar & cocoa powder alternatively with the evaporated milk until all is incorporated and add the vanilla essence – beat for a couple of minutes so its extra smooth & creamy.
- The more evaporated milk you add the more runny it’ll be, and I have found about 100ml-125ml is perfect for me! Decorate your cake how you like and ENJOY!
Notes
- This cake will last for 3 days at room temperature.
- This is the cake tin I used
- I 100% would stick with using the coffee in the cake, you can't taste it, but it helps the chocolate flavour so is important.
- The cake can take longer to bake if its over mixed - be as gentle as possible with it.
- If you can't access buttermilk, you can make your own by using 100ml of FULL FAT milk, mixed with 2tbsp of lemon juice! It will look curdled but this is fine.
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J x
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I have made enough batter for 2small cakes, can I freeze the batter, or is it better to cook and freeze the cake?
Thank you)
It’s best to bake and freeze!
Hi Jane, I am needing to freeze a birthday cake to take to my daughter and then it will have 2 days out of the freezer before the ‘reveal’. I decided on a tray bake as i think that will be easiest to transport, however will this yummy looking traybake freeze well? Thank you
Yes, it will!!
This cake has baked beautifully . Smells divine and no dip in the middle. Looks delicious. However is does seem a bit crispy on top. Took 55 mins at 140.
Can the edges be cut off or is it too delicate? Many thanks
Personally I would leave the edges as it is a smidge delicate, but thats up to you. What type of oven do you have? It may have caused the crispy top! x
Thank you for your prompt reply. I have a fan oven . I must say this cake is delicious. My grandchildren decorated it with white chocolate buttercream and berries to make a flag cake. It went down a treat. I froze it after baking snd did cut the crispier edges off whilst semi frozen. It coped very well and I shall be making it again. Perhaps I should turn the fan off next time .
Many thanks for a delicious recipe
Ca n this recipe be substituted with self raisng flour?
Hiya! Sadly not – because of the other ingredients in the cake, you need to stick to plain flour otherwise the texture will be wrong. Hope this helps! x
Would this be ok in an 8 x 12 tin? Or would I need to reduce the ingredients?
Thanks for another great recipe. Do I need to let the chocolate mixture to cool before adding it to the dry ingredients ? Thank you
Hiya! Yes, for a few mins! Hope this helps x
I made this cake and it dipped in the middle, I done everything exactly how it stated. I don’t know what went wrong it’s my 3rd attempt and same thing each time.
Hiya! This means it was likely under baked. Hope this helps! x
Can I use whole milk instead of evaporated milk in the frosting?
Hiya! You can use some, but it will not have the same effect unfortunately. Hope this helps! x
I’m on a diet and daughter wanted to bake a cake, sooooo me being undoubtedly clever decided on this chocolate tray back as I don’t really like chocolate cake, win win! happy daughter and I stay in my calories, however, it turns out I really really love this cake! It looked really squidgy and I was worried that it wasn’t cooked in the middle. Oh but it was, just unbelievable fudgey lushness
This cake is incredible! I’m using it for a number came I’m doing and I did a practice one and took it to my mums and it just flew out of the tin!!! It’s very much like a brownie in my opinion not a sponge but I’ll definitely be using it as a staple! I had a tin that was only 12” long and left it in for 1hr 10 mins and it’s perfect
Thankyou!
Is that 250g caster sugar and 250g light brown sugar? So is it 500 g sugar altogether? Can someone help
with this please as I am going to bake it tomorrow.
Thank you
Yes, that is the total weight!!
Made for my husband’s birthday and it was delicious! It did seem to be super crumbly though, is that usual? Or could it be caused by using sour cream instead of buttermilk (what I had at the time)? Thanks for the recipe!
Hiya! So glad you loved it! Yes, it could be due to this, but this sponge is very delicate so it may have been slightly over baked. Hope this helps x
This is a lovely recipe’ very moist and quick to make. Will make again.
Can I make this egg free? Thank you
The recipe states caster sugar but the method says golden caster sugar?
Excellent recipe, and I understand why the coffee granules is needed. I did use slightly less chocolate, coco-powder and sugar, and the result was more to what I preferred. Definitely the final product was a lot greater than I thought (in size) and from seeking a recipe of a simple chocolate tray bake (sometimes you can’t beat the simple bakes), I would highly recommend this cake to all.
Can I use light brown sugar instead of caster?
Hiya, yes that will be yummy!x
Love this recipe and have made it twice but each time the middle of my cake has dipped and gone slightly crispy in comparison to the edges which stayed soft.
Any advice on where I’m going wrong?
Thanks
This cake is delicious! And so easy to make!! It got gobbled up in seconds. One question I have is how do I make the icing slightly less sweet? I live in Australia (used to live in UK) and I think the icing sugar is sweeter here.
I wouldn’t use the evaporated milk as that adds more sweetness, or use slightly salted butter!
I made a double layer version of this for my dad’s 70th birthday cake, everyone loved it!
Perfect chocolatey, fudgy, spongy cake.
Simple to make but tastes amazing!
Made this yesterday for a colleague’s birthday and it was such a hit!!! Amazingly chocolatey, rich, fudgey, gloriously decadent and takes birthday cake to a whole new level. This is definitely going in my book of things to make again!! Stunning recipe! Thank you!
Hey! Ahh I am so so happy you loved it, thank you so much xx
Really delicious cake! So
Soft and Chocolatey.. but mine also sunk a little in the middle and i didnt open the oven till the end.. at 55 minutes which it was cooked by then too.. could it be too much baking powder?
Yes it definitely can be too much – raising agents need to be measured so accurately! x
I had the same issue. Really annoyed me 😭
If I wanted to make a smaller cake (8×8) using this recipe would you recommend I just half the recipe?
Tastes great. But both a friend and I have made this and both cakes sunk in the middle. Mine wasn’t over mixed, cooked for 55 mins and oven wasn’t opened during cooking. Any ideas please?
Made this over the weekend, it’s amazing and so much of it! Can’t wait to tray another one
Hi. I absolutely loved this recipe and I was wondering if I could put the mixture into cupcake cases to make chocolate cupcakes? Would this work?
Have a look at my chocolate fudge cupcakes post as its designed for it x
Will this recipe cut in half to make 2 layers or should i double the recipe? x
It’s a very delicate sponge so I think if you froze the cake it would be okay to cut, but otherwise you may struggle to cut it! Double would be fine baked into two tins, just a lot of cake! x
Hi Jane
I would like to make a vanilla version for this with a vanilla topping. Is there any way I can do this?
Not with this recipe unfortunately x
Hi, I was just wondering what brand of cocoa powder you use. Also, your recipes are amazing, they always come out delicious!
I use cacao barry as I buy large amounts (you can buy it on amazon)! And thank you!
Hi Jane! I have baked this cake so many times and it is such a treat, I get compliments all the time! I wanted to bake two of the tray bakes for work and a the Choc fudge loaf cake for work next week (it will use up all the buttermilk then!). My question was how can you convert this recipe to a 8 inch square tin or a 9 inch square tin? I had some leftover Nutella buttercream from 2 batches of cupcakes I baked a fortnight ago so I thought I could just slather it on a square cake so it doesn’t go to waste. Thanks and love all your recipes!
The best website to use for conversions I find is this one – http://www.cakebaker1.co.uk/apps-for-bakers/baking-tin-size-conversion-calculator/ x
Absolutely LOVE this traybake! I made it for my brother’s birthday in June and then for my sister’s birthday in October! It’s very dense and fudgey, almost like a brownie but is absolutely delicious!
Hi,
Using the coffee does this make the cake taste of coffee??
No not even slightly – honestly, just makes it taste more chocolatey!
Hi this is the second time I’ve tried making this cake .. both times it’s overflowed and I’ve baked it for around 1hour 15 minutes and it’s still quite raw in the middle and burnt on the edges .. what am I doing wrong ?
Are you sure you are using the correct size tin? Or it is deep enough? It definitely shouldn’t over flow so that may be the issue. x
So far so good. I have made the cake but I am not sure when to make the frosting. Should I make it half way through baking or whilst its cooling? And if I make it too early can I refrigerate it?
Always do it once the cake is out of the oven and cooling – you can’t decorate until it’s fulled cooled. x
Can you use any strength dark chocolate?
Personally I recommend 70% or darker when baking x
Absolutely delicious! Thank you!
Are you able to pipe the frosting into flowers onto the cake or will it be too soft?
I would say this frosting is too soft xx
Hi Jane I can only find a 9×12 traybake tin will this be ok to use with same measurements for ingredients? X
Yes that should okay, may take a smidge longer to bake x
Hi Jane
This looks delicious. Do you think it will work with fondant on top? I need to bake a Traybake with a theme for a party.
The frosting is quite soft, but if you are just putting a layer on top it may be okay..!
Have been baking during lockdown for various charities and found you through one of the other bakers. Have made so many of your tray bakes for NHS and vulnerable people. They are all so good. Made this one yesterday. OMG so good. Want to make another one with the buttermilk and evaporated milk that I have left over. Does the cake freeze well? Obviously without the frosting..
Hey! Yes it does freeze well!! And I’m so glad! xx
Hi Jane!
Just 1 more question if that’s okay – Is there anything I can do or any changes you would reccomend i make to prevent the cake from coming out of the oven more like a moist brownie?? (Tastes AMAZING still – but wanted it fluffier like yours)
Thank you so much x
If a cake is dense it usually means it needed longer baking – although the texture of this sort of fudge cake is denser than a normal sponge! xx
Hi Jane!
Would i be able to double the ingredients to make this 2 tier? Or would you advise against this?
Thank you!
You would need to bake the sponges separately, and it is quite deep so that would be a whole lotta cake!! x
This is the 2nd cake I’ve made from this site. This one was just as good. It was lovely and I will make again. It didn’t last long and it was all adults no children. Next cake I’m trying is the biscoff cake for a birthday next week.
Hi, I absolutely love your recipes so going to give this one a go today as I love your chocolate fudge cupcake recipe! I only have either a 9×9 or 8×10 tin.. would you adapt the recipe or the cooking time? X
I would use maybe 2/3 of the recipe? I’m not sure on timings but it would definitely be less x
Did you try it? I want to make it smaller too. Like 9×9 or 8×8.
Hi Jane,
I am having trouble getting hold of light brown sugar at the moment – is there another sugar that I could use instead?
Caster sugar, golden caster or dark brown sugar! x
Hiya!
Can I use stork instead of butter in the cake?
In the cake you can, yes!
Hi, just wondered what you do with the rest of the evaporated milk? Thanks
You can freeze it! I often buy the mini tubs so there’s less leftover!
That’s great thank you. I could only get a big 400ml tin and didn’t want the rest to go to waste. Your recipes are amazing!
Could you please recommend a gluten free switch? 🙂
I made this with 125g of brown sugar instead of full amount, as I always try to reduce sugar a bit as find it too sweet., it turned out perfect – soft delicate very chocolaty cake, still very sweet. I will try to reduce the caster sugar next time and post how it goes for those that may be interested 🙂 I didn’t ice it this time.
Hi Jane, can I used this recipe in cake tins instead of a traybake? Thank you I love all your recipes! Xxx
Have a look at my chocolate fudge cake recipe as that is already a round cake version!
Hi Jane,
I baked that cake for my son’s birthday as he is chocolate fun. My family loved it and my both kids couldn’t stop eating the cake. 🙂 Thanks for the recipe, definitely I’ll try some other cakes. xx
Ahh yay! Amazing! I love these sort of cakes for kids birthdays! x
Hi Jane!
Massive fan of your recipes!
A very silly question, I believe there used to be calories on the recipes but I can’t seem to find it anymore.
Have they been taken away?
Thank you!
Emma
Love this recipe but can you freeze the cake?
Yes!
I made this gluten free by just substituting the flour for gf but it was a bit of a disaster. It was in the oven for 1hr 20mins but still didn’t really seem to cook, don’t know whether adding Xanthan Gum would have made a difference. It tasted nice though. Kids had it with custard as it was too uneven and soft to ice.
Unfortunately, this cake is very delicate as it is and probably isn’t a simple switch no. I would have suggested adding xantham gum. If you ever want to know about switches I recommend asking first just in case!
Can I pipe with the frosting instead or is it too runny of a consistency to pipe with?
It can be piped as I use the same for my chocolate fudge cupcakes, but it’s definitely a softer consistency than normal. You MUST use real butter, and not any form of spread, otherwise it will be way way too soft!
Made this today mines took 55mins to cook. but sunk a little in middle, but when icing went on you wouldn’t notice well what can I say it was absolutely beautiful didn’t even taste the coffee (I detest coffee) will definitely be making again
Hi, my husband is pre-diabetic so has to be careful not to have too much sugar. Do you think this would work if I used wholemesl self raiding & Coconut sugar or Total Sweet xylitol in the cake? I’d prob make a thinner icing. Or any other suggestions for a birthday cake?
I would advise looking for a recipe specific to low sugar/no sugar as it’s quite key to this one!
oh my goodness 😍 what a great recipe for a chocolate cake!! I’ve been baking at home for years but never thought of adding evaporated milk to buttercream… YUM!! I found my cake took about 15 mins longer to bake than recommended at 140°. Will definately be baking this one again 😁
Hi, will this work with sour cream?
I would recommend buttermilk as the recipe says for the best bake.
Hey Jane,
I attempted this last night and although the cake is moist and tastes amazing, it sunk in the middle and just falls to bit when you try and pick it up. What have I done wrong and how can I fix it for next time? Thank you! X
If it sunk in the middle it probably wasn’t quite finished baking – the cake is very delicate as well but that’s part of its delicious charm! x
These look amazing and I can’t wait to make. My mums coeliac so as usual for us they’ll be gf. Have you made this traybake gf before? Can’t decide between these and some of your other gf recipes! I know you’ve quite recently given up gluten so if need any hints or tips on the best products etc then let me know. Xxx
Hiya – I haven’t recently given up gluten, I still eat it! You could definitely try it GF however, but I haven’t with this one in particular. You would need to add in xantham gum to stabilise the mixture before, but it will most likely be extremely soft without the gluten so beware!
Hi, can you tell me if i can use an alternative to the buttermilk? I cant have dairy ( i can adapt everything else) didn’t know if i can use almond milk instead? thanks.
I’m afraid I am unsure of a dairy alternative to buttermilk – I would advise looking at a dairy free cake such as mine and covert that into a traybake!
i think u can use any other dairy free milk and add vinegar to make a buttermilk substitute
Hello!
Can you tell me how deep the cake tin needs to be? Thank you!
Hiya! I think mine is 2-2.5″ deep! Most traybake size tins are similar! x
Hi Jane, please could you tell me what the oven temperature is for this delicious cake? My cake seemed to come out a little raw 🙁 still lovely though!
Its 160C, or 140C for a fan oven – as mentioned, it can take longer for some ovens to bake the cake. If it’s raw, it wasn’t finished baking.
I often find that the supermarket traybakes are quite dry, so i’m definitely trying this! I just found your website and it has given me so many ideas x
I hope you love it! X
Hii,
I’m not really a fan of dark chocolate (too strong)
Can I use milk Chocolate instead?
You can’t taste it once it’s baked into the cake, I would only use dark chocolate. It makes it delicious, and it’s not too dark after.
I tried this today and was very excited but something has gone wrong. I opened my oven after 40mins and my cake seems as though it has sunk but the middle section is crispy. Do you have an idea what I have done wrong 😞
I think you opened the oven too early, so it sunk and baked weirdly. The temperature can change up to 10 degrees for every second the oven is open, so if it was too early for the bake it would have affected it quite badly!
Hi Jane,
This is the first recipe I’ve made from your blog and I think I will have to try lots more! It was absolutely beautiful and I got so many compliments on it. My frosting was a lot paler than yours, I wonder if I did anything wrong? But it tasted amazing anyway
It was probably down to the cocoa powder – which one did you use? x
All I had was some from Lidl, that was probably it! Thanks x
Sometimes some just aren’t as dark or as chocolatey! I use Tescos own, and it looks so much darker than bournville for example! xx
This was amazing thank you Jane! Made if for 2 work colleagues leaving today & added smarties & maltesers for decoration – just incase there wasn’t enough chocolate already lol! Loads of posititve comments from my work mates & not much left when I left mid afternoon!
Any chance you could do a recipe for a similar traybake but with no chocolate (or white chocolate) as my husband gets migranes from milk & plain chocolate & missed out on the deliciousness! Thanks a million
Hiya! I have other recipes scheduled in, but I don’t like post similar recipes like this too close together so it is coming! But I’m glad this one was enjoyed!!
Hi – loving your blog. Think you might want to check your U.S. conversions from Metric on this recipe as they seem all over the place e.g. sugar, coffee, and bicarb.
It’s all done automatically, I don’t do the conversions myself.
Can I cut out one of the sugars as in just put 250g instead of 500?
I wouldn’t advise it – to get what’s in the pictures, you need to use the recipe.
cake looks good but i t drink coffee so i wont go get coffee to make this cake. i can tell there something different when added coffee/ cuz friend made cupcakes using coffee and i could tell theres a different in taste.
I completely disagree as I don’t drink coffee at all as I’m really not a fan, and I can’t taste it in this, but that’s up to you. x
Hey! Love you recipes. Can you just confirm the cooking time please. In the intro it says 35 mins and then 50-60 in the instructions? Thank you xx
Ooh it appears it calculated it wrong haha! It’s the 50-60. x
Fab! I have a dodgey oven anyway so will take as long as it takes haha. Will make sure to tag you on Instagram! Thank you
Hahaha mine used to be so I know what you mean!! Enjoy!
Does this recipe really use 500g of sugar or is it a misprint? It seems rather a lot.
500g is correct. As you get so many slices from it, it’s not that much per portion.
Thank you. I went ahead and made it and I must say, it’s one of the most delicious chocolate cakes I’ve tasted…….my husband has even requested it instead of an actual cake for his 40th birthday in November! Thank you for sharing your wonderful recipes, I haven’t found one yet that hasn’t been amazing! 😊
Ahh amazing!!!
How deep was the tin you used?
Hi what brand of dark chocolate do you use?
It can really range, but most often or not its supermarket own basic dark chocolate! X