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A deliciously yummy chocolate school cake with a really easy-to-make chocolate cake, icing, and homemade chocolate custard! 

Oh, helloooo, you utterly delicious recipe that I just cannot get enough of already. Honestly, this chocolate school cake is a little life-changing for me, because I am just obsessed and I would like to eat it all day every day! 

As always, this was a recipe that had been endlessly requested, so here it is! It’s a yummy chocolate version of the ever classic school cake recipe that is already on my blog 

Classic Bakes

Now I have nearly 700 recipes on my blog, and many many more in my first book and second book, but classic bakes often win out above anything and I cannot blame you for that. There is something about the simplicity and classic flavours that will just give you a whack of nostalgia and it’s all you want to eat. 

I am all for so many delicious recipes and baking ideas, but there is something about what you used to eat when you were younger, such as the classic school cake, butterfly cupcakes, jammy coconut cake, rhubarb, and custard-themed bakes and so on – they are all just so scrumptious. 

This beauty comes under the ever-amazing category of school-related bakes from your past, that you will want to recreate asap. 


The cake is simple as always as it should be; it’s basically a chocolate victoria sponge-style recipe because that’s all you need to create something this good. It comes under the idea of a classic bake for me where you don’t need anything fancy at all, and it’s often ingredients that are already in the cupboard. 

  • Butter – As always with a classic sponge, you can use a block of proper unsalted butter at room temperature, or you can use a baking spread!
  • Sugar – Caster sugar is my go-to for a cake like this as it’s often the sugar that’s most used for people, but light brown sugar would work well, also!
  • Flour – I use self-raising flour because you want the raising agent to create a lighter texture that is delightful
  • Cocoa – The cocoa powder is obviously fairly important because it’s the quickest and easiest way to get to a chocolate-based bake.
  • Vanilla – The vanilla is optional, but I find it so so delicious in this bake. 


I tend to cream my butter and sugar together until light and fluffy, and then add the other ingredients. Some people do the all-in-one method, but I find this can be risky because if your butter is too cold for example, you could end up with a split mixture or lumps of butter throughout the mix which is then hard to fix.

For a cake like this, it’s not small… but that’s okay, as it’s only one layer! I use a classic 9×13″ traybake tin because it’s the ideal size, and the amount of cake mix is ideal. 

You never want a cake like this to be in too small a tin as the cake slices are going to be too deep, whereas the 9×13″ is perfection. 

You want to bake the cake until there is no cake mix on a skewer that you poke into the middle of a cake so that you know it’s not going to sink or anything once taken out of the oven. Another method to test if you are still unsure is to listen to the cake; if it’s making a bubbling or crackling sound, it still needs a bit longer in the oven. 


When I was originally making this cake, it didn’t have icing… and that may be what some people are expecting. I found when it came to a chocolate school cake, some had it plain with the chocolate custard as that is often enough, but others had a simple icing. 

I decided to do a chocolate school cake recipe WITH icing so if you want to make it, you can, or you can just leave it off. It’s such a simple icing though it’s worth trying as it’s just so so SO easy to make! 

A normal water icing consists of icing sugar and water, and that’s it. I use the addition of cocoa powder to make a rich and delicious-looking icing that is still sweet and tasty, with a sprinkling of sprinkles all over of course. Let this set somewhat, and then portion and enjoy. 


So when it comes to custard, you can 1000000% cheat and buy a shop-bought custard – we don’t judge here at Jane’s Patisserie (sometimes, you just don’t have the time to make something from scratch and that is totally okay. 

An easy way to make a chocolate custard is to buy a shopbought custard whether it’s a fresh one from the chilled aisle, or a long-life custard is to heat it up in a pan, and add chopped chocolate! You can let the chocolate melt into the custard and it leaves it thick and delicious. 

If you want to make your own, however, this custard is so easy to achieve and I make it so often now.

  • Milk – You need to use FULL-FAT milk to achieve the thick goodness of the custard. 
  • Egg yolks – when you make a custard from scratch it is a classic to only use egg yolks as you want the richness of the yolk (the white has no place here)
  • Sugar – I use caster sugar because it’s what I used in the sponge, but again you can use light brown soft sugar if you fancy. 
  • Flour – This may sound weird, but it’s important as it helps thicken the custard and make it delicious. 
  • Flavour – Again, I use a little vanilla because yum
  • Chocolate – I decided to use an equal split of milk chocolate and dark chocolate to get a good balance, but you can use all of one or all of another. 

Tips and Tricks

So after all of that, you should be able to make a deliciously easy chocolate school cake with no worries (but as always, any questions? leave them below in the comments!). 

The most important thing with a bake like this, especially if you are involving your kids over the summer holidays, is HAVE FUN!!! Jane x

Chocolate School Cake!

A deliciously yummy chocolate school cake with a really easy-to-make chocolate cake, icing, and homemade chocolate custard!
Print Pin Rate
Category: Cakes
Type: Traybake
Keyword: Chocolate
Prep Time: 30 minutes
Cook Time: 45 minutes
Cooling & Decorating Time: 2 hours
Total Time: 3 hours 15 minutes
Servings: 15 People
Author: Jane's Patisserie



  • 400 g unsalted butter
  • 400 g caster sugar
  • 8 medium eggs
  • 325 g self raising flour
  • 75 g cocoa powder
  • 1 tsp vanilla extract


  • 400 g icing sugar
  • 50 g cocoa powder
  • 4-5 tbsp water


  • chocolate sprinkles

Chocolate custard

  • 4 egg yolks
  • 30 g caster sugar
  • 30 g plain flour
  • 300 ml full-fat milk
  • 1 tsp vanilla extract
  • 50 g milk chocolate
  • 50 g dark chocolate


For the Cake

  • Preheat your oven to 180C/160C Fan and line a 9x13" Traybake tin with parchment paper.
  • Beat together your butter and sugar until light and fluffy.
  • Add in the eggs, self raising flour, cocoa powder and vanilla extract and beat again until combined well. 
  • Pour into the tin and bake in the oven for 45-50 minutes, or until baked through. 
  • Once baked, let the cake cool fully in the tin.

For the Icing

  • Add the icing sugar and cocoa powder to a medium sized bowl, and gradually add the water, mixing well each time, until a thick icing paste is made.
  • Carefully spread the icing over the cake evenly.


  • Sprinkle over your favourite chocolate sprinkles!


  • Add the egg yolks, sugar, and flour to a large pan and whisk until smooth. Start to heat the egg yolk mixture on a low heat
  • Pour in the milk gradually whilst whisking, and pour in the vanilla extract
  • Whilst whisking continuously, heat the mixture to a simmer and let it simmer for several minutes until it starts to thicken
  • Once starting to thicken, add the milk chocolate and dark chocolate and let this melt whilst still stiring
  • Continue to heat the custard until you reach your desired consistency
  • Serve with the cake immediately if you want it hot, or let it cool for cold custard!


  • I recommend using a 9x13" Traybake tin for this recipe. 
  • This cake will last for 3-4 days once made. 
  • For a 9" square tin - I would recommend a 5 egg/250g sugar/butter/200g flour/50g cocoa mixture. Baked for 35 minutes

Find my other recipes on my Recipes Page!

You can find me on:

J x

© Jane’s Patisserie. All images & content are copyright protected. Do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words and credit me, or link back to this post for the recipe.






  1. Jamie on February 15, 2024 at 8:39 pm

    5 stars
    Hey. Can this cake be frozen?

  2. Julie on September 10, 2023 at 1:41 pm

    Hi I want to make the smaller version I see the lower amount of ingredients for the cake but what about the icing how much less of everything for it please and thank you

  3. Trisha Garrod on August 30, 2023 at 8:17 am

    Hi Jane, I’m making a 70th number cake 7 vanilla & 0 chocolate, for my sister next month and wondered if this recipe and your vanilla tray bake would be suitable to use or could you recommend a different recipe of yours for it please. Thank you 😊
    I’ve git 2 of your books an waiting to order the new one x

  4. Lisa on August 9, 2023 at 12:15 pm

    If I was to substitute for gluten free flour what would the measurements be? Would I also require xanthum gum?

  5. Rads on June 21, 2023 at 8:53 pm

    Hi Jane! I would like to make this sponge into a chocolate coconut sponge similar to the jammy coconut sponge. Do I add the same amount of coconut (125g) to this mixture and leave the rest of the ingredients the same? x

  6. Lizzy on May 16, 2023 at 4:12 pm

    Hi Jane,
    Could I use chocolate buttercream for this cake instead? If so, could you tell me measurements please?
    Thank you.

  7. Andrea Stenner on March 24, 2023 at 11:24 pm

    Hi, how much custard does the custard recipe make, please?

    Also, please can you create a recipe for Cadbury’s, Bournville & White Chocolate Trifle making it all from scratch. I think the mouse would be lovely layered in the 3 types of chocolate I have mentioned & the custard would be nicely made with chocolate also with either a chocolate Swiss roll or gooey chocolate brownies for the base.

    I love your recipes and books.

  8. Hazel on February 27, 2023 at 4:50 pm

    Hiya i want to make this cake for my sons birthday, do you think i should bake 2 of these or would the one be thick enough to cut through the middle to make 2 layers? xx

    • Jane's Patisserie on March 2, 2023 at 9:34 am

      Hiya! This is a fairly chunky sponge so should be okay to cut if chilled first – though if you’re worried, just bake a second sponge and you can freeze it for the future if you don’t use it! Hope this helps! x

  9. Isma on December 21, 2022 at 5:50 pm

    Hi how much icing and coco powder do I need to use for the icing if am using a 9inch square tin?

  10. Michelle on November 26, 2022 at 11:05 am

    Do you have a white chocolate recipe for this??

  11. Carlie on November 16, 2022 at 4:34 pm

    5 stars
    Hi, I absolutely love your recipes you have bought back my love for baking.
    For the custard in this recipe can you use semi skimmed rather than full fat milk?
    Thank you 😊 x

    • Jane's Patisserie on November 28, 2022 at 4:04 pm

      Hiya! Unfortunately this will make it quite thin – but if you don’t mind that, give it a go! Hope this helps! x

  12. Emma on October 6, 2022 at 2:48 pm

    How do you store it? Air tight tupperware or card cake box?

    • Jane's Patisserie on October 6, 2022 at 3:05 pm

      Hiya! I usually store in air tight tupperware. Hope this helps! x

  13. Liza on September 16, 2022 at 11:38 am

    Hiya. Recipe looks great!
    I wanted to make this but in 9 inch round tins.
    Would this cake work with chocolate buttercream please?

  14. Lyn parker on September 11, 2022 at 10:11 am

    5 stars
    Brilliant recipe

  15. Karen Forrester on August 29, 2022 at 12:21 pm

    Hi Jane I just want to say I love your recipes, so tasty and easy to follow. would like to make this recipe in a 12”x 12” tin but I’m having trouble trying to work out how much to increase the ingredients by. What would you suggest? Thank you.

  16. Tracy R on August 27, 2022 at 12:02 pm

    5 stars
    Hi Jane…loving your recipes as always. Can you recommend a fudge/ganache type topping for the chocolate school cake? So not a buttercream…not icing but ganache which sets really firmly which is spreadable but won’t run down the sides. Thank you

    • Erica on March 2, 2023 at 6:02 pm

      A water ganache is perfect for this cake. 500g of plain dark choc with 200g of cold water. Place in a microwavable plastic bowl and heat on medium in for 1 minute at a time. Once melted, whisk with a balloon whisk until smooth. Leave at room temp until it is a good consistency for spreading. It firm’s up well 👌

  17. Jo on August 21, 2022 at 8:31 am

    Jane you are killing me. If you keep making these things I’m going to be the size of a house haha! I’m loving this one – making it for my family today as pudding for after a Sunday roast! Perfect as always!

  18. Lisa on August 20, 2022 at 1:30 pm

    I never got to have the school chocolate cake and custard because I was dairy free at that age …. I’m still dairy free but I now eat butter, I’m also gluten free but that’s easily remedied in a recipe like this so I’m going to enjoy having something that I was never “allowed” before 😊

  19. Michelle on August 19, 2022 at 7:08 pm

    Any way to get measurements in ounces, rather than gram weight?

  20. Kirstin on August 16, 2022 at 9:29 am

    5 stars
    This sounds perfect to bake with my 2yr old, he loves baking! Quick question though, if I’m going to make the 9 inch square recipe, how much of the icing would I need?

  21. Sharon Bacon on August 15, 2022 at 7:12 pm

    5 stars
    Hi Jane
    Love, Love , Love your bakes!!! I’ve bought both books now… !!
    Where do you get the Chocolate Sprinkles from please? Xxx

    • Jane's Patisserie on August 16, 2022 at 1:13 pm

      Hiya! They are just from my local supermarket! Hope this helps! x

  22. Jan on August 15, 2022 at 3:50 pm

    Hi Jane,

    I thought you were GF now? Do you still taste bakes that aren’t like this one?
    Looks amazing BTW!!

    Jan 🙂

    • Jane's Patisserie on August 16, 2022 at 11:50 am

      Hiya, I have never been gluten free – only tested to be a coeliac for a short while, once.

  23. Aysha on August 15, 2022 at 12:05 pm

    Hi Jane,
    Thank you for all your great recipes! Quick question- if I only had large eggs how many would I use?

    • Jane's Patisserie on August 16, 2022 at 1:13 pm

      Hiya! I would use 6 large eggs. Hope this helps! x

    • Yvonne Youngman on August 25, 2022 at 11:12 am

      5 stars
      Hi, for the square tin recipe – how much butter should I use?
      Excited to make this for my chocolate mad boys!
      Thanks x

  24. Boo Clarke on August 15, 2022 at 9:55 am

    I love all your recipes – every one I’ve ever done has been delish with so many comments about what a marvellous baker I am🤣🤣😉

    I do have a question, though – are you able to choose the adverts that go into your blog, or do they just pop up willy-nilly?! There are always so many that appear on instagram etc, it would be nice to know which ones are trustworthy or not.

    • Jane's Patisserie on August 16, 2022 at 4:25 pm

      Hiya! All adverts on my blog are trustworthy, they are run through google and are responsive to your individual searches! Hope this helps! x

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