Say hello to the BEST Chocolate Traybake – a.k.a Chocolate Sheet Cake! This moist chocolate cake topped with decadent chocolate frosting is perfect for birthdays, celebrations and bake sales. And the best part? It is SO EASY to make!
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Tray bakes are currently in vogue – just look at the runaway success of Edd Kimber’s One Tin Bakes (an awesome baking book, highly recommended).
The reason? They are easy peasy, low effort, take mere minutes to prepare AND they can feed a crowd. Perfect for fuss-free birthday parties when you haven’t got the time to create a big layer cake.
This foolproof chocolate tray bake recipe is my go-to cake whenever my kids want to bring something to school to celebrate their birthdays. I can tell you that there’s never a crumb left 🙂
Fans of my Retro School Cake will LOVE this chocolate version of their favourite recipe!
Here’s what you will need
- Plain flour (all purpose flour) plus baking powder and bicarbonate of soda.
- Sugar: ideally half caster and half soft brown sugar
- Cocoa powder: use the best quality unsweetened cocoa powder
- A little espresso powder: this enhances the chocolate flavour but if you prefer not to use any you can simply leave it out
- Three medium eggs
- Softened butter or margarine (I used Stork in the recipe video)
- Buttermilk or milk plus a little lemon juice
- Softened butter
- Icing sugar
- Cocoa powder
- Milk, heated in the microwave for 30 seconds until a little warm
- Melted chocolate: use good quality dark chocolate
Useful Tools & Equipment
- Digital scales – I use a scale for all my bakes
- Measuring spoons
- A rectangular cake tin
- Cake lifter – for transferring cakes safely
MAKE THE CHOCOLATE SPONGE CAKE
Make sure your ingredients are at room temperature. Put the flour, sugar, cocoa powder, baking powder, bicarbonate of soda and espresso powder in a mixing bowl (or the bowl of your stand mixer). Use a balloon whisk or fork to stir so they are combined.
Add the softened butter, eggs, buttermilk and mix together on low speed initially, increasing to maximum speed until batter is smooth. Make sure to use a spatula to scrape the bottom and sides of the bowl to ensure no sneaky dry pockets of flour lurk underneath!
Transfer the batter to a lined rectangular tray (9×13 inches) and bake in a preheated oven for 35-40 minutes. Test the cake is done with a skewer – it should come out clean and crumb free. The cake should be risen and just coming away from the edges of the tin.
Cool the cake in the tin for 10 minutes then use the overhanging paper to carefully lift onto a wire rack to cool completely.
MAKE THE CHOCOLATE FROSTING
Put the chocolate in a bowl and melt in the microwave, in short 30 second bursts, until it melts. Alternatively, set the bowl over a pot of simmering water and allow if to melt gradually using this double boiler method. Leave the chocolate to cool slightly.
Put the icing sugar and cocoa powder in a mixing bowl (or the bowl of your stand mixer) and mix together to combine. If you can, sift the ingredients into the bowl. I must admit I am usually too lazy to do that!
Add the softened butter and start mixing on low speed, gradually adding the milk until frosting is well combined. Add the melted and cooled chocolate and beat together until the frosting holds soft peaks. Go ahead and taste it… try not to eat it all!
ASSEMBLE THE CHOCOLATE TRAYBAKE
Use a palette knife to spread the frosting over the cake, swirling the surface. This cake has A LOT of frosting (if you haven’t eaten it beforehand).
Add sprinkles, chocolate buttons, smarties or leave plain. When you are ready to serve, slice the cake using a serrated knife, wiping the knife clean between each slice.
This chocolate sprinkle cake will keep for 2-3 days at room temperature but it is best eaten when fresh.
My Most Popular Cake Recipes
- 300 g (2 ½ cups) flour plain / all purpose
- 60 g (½ cup) unsweetened cocoa powder
- 330 g (1 ⅔ cups) sugar use half granulated, half light brown if you like
- 1 tbsp espresso powder (optional)
- 1 tbsp baking powder
- ½ tbsp bicarbonate of soda
- ½ tsp salt
- 200 g (7/8 cup) unsalted butter or Stork softened
- 3 medium eggs
- 180 ml (3/4 cup) whole milk
- 2 tbsp lemon juice to sour milk (or use buttermilk)
- 260 g ( 2 cups) icing sugar
- 6 tbsp unsweetened cocoa powder
- 150 g (⅔ cup) softened unsalted butter
- 120 ml (½ cup) milk slightly warm
- 175 g (1 cup) dark chocolate chips melted and cooled
- chocolate sprinkles, M&Ms, chocolate shavings
- Preheat the oven to 170C (340F). Line a 9x13inch rectangular with baking paper.
- Mix the milk and lemon juice and leave to stand for 5 minutes.
- Put the flour, cocoa powder and sugar in large bowl. Add the baking powder, bicarbonate of soda and salt and mix together using a balloon whisk.
- Add the butter, eggs and soured milk.
- Start beating on the lowest speed setting until the ingredients start to come together.
- Increase the speed gradually, until the batter is completely smooth. Stop the mixer and scrape the sides and bottom of the bowl to make sure everything is incorporated.
- Transfer the batter in the prepared tin and level.
- Transfer the batter into the prepared cake tin and bake for 35 -40 minutes.
- Check the cake is done by inserting a skewer in the centre – it should come out clean, the cake should be well risen golden and springy to the touch. Cool the cake before frosting.
- Put the chocolate in a bowl and melt in the microwave, in short 30 second bursts, until it melts. Alternatively, set the bowl over a pot of simmering water and allow if to melt gradually using this double boiler method. Leave the chocolate to cool slightly.
- Put the icing sugar and cocoa powder in a mixing bowl (or the bowl of your stand mixer) and mix together to combine. If you can, sift the ingredients into the bowl.
- Add the softened butter and start mixing on low speed, gradually adding the milk until the frosting is well combined.
- Add the melted and cooled chocolate and beat together until the frosting holds soft peaks. Go ahead and taste it… try not to eat it all!
Assemble the Cake
- Use a palette knife to spread the frosting over the cake, swirling the surface. This cake has A LOT of frosting (if you haven’t eaten it beforehand).
- Add sprinkles, chocolate buttons, smarties or leave plain. Slice the cake using a serrated knife, wiping the knife clean between each slice.
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