This old school chocolate traybake cake is so simple but super delicious! It's a soft, fluffy chocolate sheet cake topped with simple chocolate glace icing and chocolate sprinkles.

I'm back with another old-school cake recipe, this time it's a chocolate one! I recently posted my vanilla school dinner cake recipe as well as my jam and coconut sponge cake, and my Cornflake tart traybake has proved to be a hit so far. So naturally, chocolate cake traybake just had to come next!
This cake is super easy to make and uses less than 10 simple ingredients so it's great for kids to help with. It's perfect for a simple birthday cake, a bake sale treat, or an after-dinner dessert. It's even more amazing served with warm custard, which is how they used to serve it at my school in the 90s. I can't wait for you to try it!
For the readers who are new to cake baking, I've written out detailed notes, tips and step-by-step images with photos in the post below. I hope this will help you get success on the first try. And for the more experienced bakers, there's a short, condensed version of the recipe in the card at the end of the post. Enjoy!

Ingredient notes
- Butter: Use unsalted butter for this cake- you can add a pinch of salt separately to the cake mix if you like but I personally don't. Make sure to soften the butter before baking by letting it sit out at room temperature for 60 minutes.
- Caster sugar: Caster sugar is a finer version of granulated white sugar and helps to improve the texture of baked goods. It's also known as superfine sugar in the USA.
- Eggs: Eggs bind the rest of the ingredients together and help with leavening. You'll need 4 medium eggs for this cake.
- Vanilla extract: To add extra flavour. If you want to really enhance the chocolate flavour, you can swap this out for a teaspoon of cold espresso. You won't taste the coffee at all but the chocolate flavour will be more intense.
- Self-raising flour: Self-raising flour is the best type to use for this cake to get the perfect fluffy texture. If plain/all-purpose flour is all you have, you can use it as a 1:1 substitute alonge with 2 teaspoons of baking powder.
- Milk: 3 tablespoons to help loosen the cake mix.
- Cocoa powder: For the chocolate flavour. We'll use this both in the cake mix and in the glace icing.
- Icing sugar: Mixed with cocoa powder and a small amount of milk, this will create a thick, glossy icing that goes perfectly with old school chocolate traybake cake.
- Chocolate sprinkles: The finishing touch! I used chocolate strands but feel free to use whichever ones you like best.
Equipment/tools
- Kitchen scales: When it comes to baking, accuracy is important. I recommend using grams to measure, which is why I usually don't include imperial measurements in my recipes.
- 8x10-inch tin: This is the size of tin I always use for my cakes so use this if you can. It will help you get a nice, thick, fluffy cake.
- Baking paper: To stop the cake from getting stuck. You can leave a bit hanging over each edge so you can just lift the cake out later.
- Electric hand whisk: I recommend using an electric hand whisk or stand mixer to make the cake batter. It can be done by hand but it takes quite a bit more effort.
- Bowls and utensils: You'll need a large bowl for mixing the batter and a smaller one for the icing, as well as a wooden spoon or spatula, a tablespoon, a teaspoon and a sharp knife.

How to make old school chocolate cake traybake
Step 1: Preheat your oven to 180°C (or 160°C if you're using a fan oven). Line an 8x10-inch tin with baking paper.
Step 2: In a large bowl, whisk together 250g softened butter and 250g caster sugar until soft and fluffy. Then stir in 1 teaspoon of vanilla extract.

Step 3: Measure out 220g of self-raising flour and 30g of cocoa powder. Mix it into the butter/sugar mixture along with 4 eggs and 3 tablespoons of milk. Mix them in a little bit at a time to prevent curdling.

Step 4: Transfer the cake batter to your lined tin and bake for 25-30 minutes, or until a toothpick through the middle comes out clean. Let the cake cool for about 10 minutes then gently flip it out onto a wire rack. Leave to cool completely.
Step 5: Prepare your chocolate glace icing by mixing together 190g of icing sugar, 1 tablespoon of cocoa powder and 2 tablespoons of milk. If you want thicker icing, add more icing sugar. If you want it thinner, add more milk or water.
Step 6: Spread the icing evenly over your cooled cake and top with a few tablespoons of chocolate sprinkles. Let the cake sit at room temperature until the icing has hardened, then cut it into slices and enjoy!

Top tips
- 8x10-inch is the best size of tin to use for a thick cake. I highly recommend it!
- If you don't have chocolate sprinkles to hand, you can use a vegetable peeler to create decorative curls from your favourite bar of chocolate.
- For a more decadent dessert, top your chocolate traybake with buttercream instead of glace icing.
FAQ
This cake will last for up to 5 days so long as you keep it in an airtight container. I like to store it in the kitchen cupboard but it can also be kept in the fridge if you want.
Yes. Pop your cake slices into airtight containers and freeze for up to 3 months. To defrost it, just let it sit out at room temperature on a wire rack or plate for 1-2 hours.
Yes, you can use a slightly larger tin but be aware that the cake will turn out a little bit thinner. The baking time will also differ so make sure to keep an eye on it while it's in the oven. You can use my cake pan converter for other tin sizes.
Yes, you can make this recipe gluten-free by swapping the self-raising flour for a gluten-free self-raising flour blend. If your blend doesn't already contain xanthan gum, make sure to add ¼ teaspoon of it separately to prevent the cake from crumbling.

More traybake recipes:
I hope you like this old school chocolate cake traybake recipe. If you try it at home, please leave a comment and rating below to let me know what you think. Enjoy!

Old School Chocolate Traybake Cake
Ingredients
Traybake cake
- 250 g Softened butter
- 250 g Caster sugar
- 1 Teaspoon Vanilla extract
- 4 Medium Eggs
- 220 g Self-raising flour
- 30 g Cocoa powder
- 3 Tablespoons Milk
Topping
- 190 g Icing sugar
- 1 Tablespoon Cocoa powder
- 2 Tablespoons Milk
- Few Tablespoons Chocolate sprinkles
Instructions
- Preheat your oven to 180℃ (160℃ for fan ovens) and line an 8x10-inch baking tin.
- In a large bowl, cream together the butter and sugar then stir in the vanilla extract. An electric hand whisk is handy for this.
- Whisk in the eggs, flour, cocoa powder and milk, a little bit at a time, until you have a smooth cake batter.
- Transfer the batter to your lined tin and spread it out evenly. Bake for 25-30 minutes, until a toothpick comes out clean.
- Let the cake cool in the tin for around 10 minutes then flip it out onto a wire rack and leave to cool completely.
Icing and sprinkles
- Mix the icing sugar and cocoa powder together then stir in the milk. To make your icing thinner, add more milk, and to make it thicker, add more icing sugar.
- Spread the icing on top of the cake then top with the chocolate sprinkles.
- Leave the icing to harden then cut into slices and enjoy!
Video
Notes
- Store in an airtight container for up to 5 days.
June
Made this for my grandsons birthday... yummy
Chloe
Glad you enjoyed! 🙂
Mia
Can I use this recipe if using a ‘6’ and ‘0’ cake mould?
Chloe
Yes, you might need to double the recipe depending on how big your tins are, and baking time will vary so keep an eye on them while they're in the oven.
Katherine Vervest
Loved this and so did my teens!
Chloe
So glad to hear that, thanks!
Naseem khalifa
I made this traybake and it was delicious.It was a hit. Will make again . Thank you.
Chloe
Thanks Naseem 🙂
Carol
Can I use baking spread instead of butter for this recipe?
Chloe
Yes