Easy Chocolate Cake Traybake
, Updated Feb 09, 2026
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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!
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 as pie, 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 🙂
Here’s What You’ll Need
- Plain flour (all purpose flour) plus baking powder and bicarbonate of soda.
- Sugar: ideally a mix of granulated and light soft brown sugar
- Cocoa powder: use the best quality unsweetened cocoa powder
- Espresso powder: this enhances the chocolate flavor but is completely optional
- Three large eggs at room temperature
- Softened unsalted butter or margarine
- Buttermilk or milk soured with a little lemon juice
Chocolate frosting
- Softened unsalted butter (do not use margarine in the frosting)
- Sifted powdered sugar
- Cocoa powder
- Milk, heated in the microwave for 30 seconds until a little warm
- Chocolate: use good quality semi-sweet chocolate chips (and while you are at it, take a look at my Dubai Chocolate Bar Recipe!)
How to make my Chocolate Traybake Cake
Make the cake
- Make sure your ingredients are at room temperature. Put the flour, sugar, cocoa powder, baking powder, baking soda and espresso powder in a large 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 and soured milk and beat 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 sheet pan (9×13 inches), level 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 frosting, decorate and serve!
- 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!
- 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, M&Ms or leave plain. When you are ready to serve, slice the cake using a serrated knife, wiping the knife clean between each slice.
Storing and freezing
- This chocolate cake will keep for 2-3 days at room temperature in an air tight container or cake carrier but it is best eaten when fresh.
- To freeze the cake unfrosted: allow the cake to cool down. Wrap tightly in a layer of plastic wrap and a layer of foil. Place in a suitable container or bag, label with the date and freeze for up to three months. Thaw the cake in the refrigerator overnight. Return to room temperature before adding any frosting.
- How to freeze a frosted chocolate cake: assemble the cake and place in the refrigerator for 30 minutes so that frosting can harden. Wrap the cake in plastic wrap, then foil. Place the cake, whole or in slices, it in a freezer-safe container, date and freeze for up to 3 months. Thaw in the fridge overnight and serve at room temperature.
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Chocolate Traybake
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!
Video
Equipment
Ingredients
- ¾ cup (180ml) milk
- 2 tbsp lemon juice to sour milk
- 2 ½ cups (300g) all-purpose flour (=plain flour)
- ½ cup (60g) cocoa powder natural, unsweetened
- 1 ⅔ cups (330g) sugar granulated or light brown sugar
- 1 tbsp espresso powder (optional)
- 1 tbsp baking powder
- ½ tbsp baking soda (=bicarbonate of soda)
- ½ tsp salt
- ⅞ cup (200g) unsalted butter softened
- 3 large eggs
Chocolate Frosting
- 1 cup (175g) semi sweet chocolate chips melted and cooled
- 2 cups (260g) powdered sugar (= icing sugar)
- 6 tbsp cocoa powder natural, unsweetened
- ⅔ cup (150g) unsalted butter softened
- ½ cup (120ml) milk slightly warm
To decorate
- sprinkles or candy of your choice
Instructions
Make the cake
- Preheat the oven to 340°F (170°C). Mist a 9x13inch rectangular pan with cake release and line with baking paper.
- Combine the milk and lemon juice in a measuring jug and let stand for 5 minutes to sour the milk.¾ cup (180ml) milk, 2 tbsp lemon juice
- Put the flour, cocoa powder and sugar in large bowl. Add the espresso powder if using, baking powder, bicarbonate of soda and salt and mix together using a balloon whisk.2 ½ cups (300g) all-purpose flour, ½ cup (60g) cocoa powder, 1 ⅔ cups (330g) sugar, 1 tbsp espresso powder, 1 tbsp baking powder, ½ tbsp baking soda, ½ tsp salt
- Add the butter, eggs and soured milk.⅞ cup (200g) unsalted butter, 3 large eggs
- 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 sheet pan, level and bake for 35 -40 minutes.
- Check the cake is done by inserting a skewer in the middle – it should come out clean, the cake should be well risen golden and springy to the touch. Cool the cake on a wire rack before frosting.
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.1 cup (175g) semi sweet chocolate chips
- 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.2 cups (260g) powdered sugar, 6 tbsp cocoa powder
- Add the softened butter and start mixing on low speed, gradually adding the milk until the frosting is well combined.⅔ cup (150g) unsalted butter, ½ cup (120ml) milk
- 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.
Notes
- This chocolate sprinkle cake will keep for 2-3 days at room temperature but it is best eaten when fresh.
- Alternatively you can freeze the cake for up to three months. Wrap tightly in a layer of plastic wrap, then foil. Place in a freezer-safe container, label with the date and consume within three months. Thaw overnight in the fridge and serve at room temperature.
Nutrition
Calories: 490kcal | Carbohydrates: 67g | Protein: 6g | Fat: 24g | Saturated Fat: 7g | Cholesterol: 36mg | Sodium: 439mg | Potassium: 256mg | Fiber: 3g | Sugar: 47g | Vitamin A: 941IU | Vitamin C: 1mg | Calcium: 94mg | Iron: 2mg
Nutritional information is always approximate, and will depend on quality of ingredients and serving sizes.
This tray bake is so easy to make, made it with my granddaughter twice.
Amazing, soft and tasty and lasts for days.
Thank you excellent recipe
Thanks for the kind words Paola! Much appreciated and I love that you’re making it with your granddaughter, that’s just so sweet to hear.
Good recipe however I had issues with my softened butter solidifying when it came into contact with the milk which made it hard to mix in properly. next time I’ll add the milk and butter separately or use margarine.
Yes it works best if the milk is slightly warm. Thanks for your comment and rating!
Stupid! No quantities. I’m not a mind reader.
Eloise there are of course quantities – I don’t expect anyone to be a mind reader. The recipe card at the bottom of the post has detailed instructions and ingredients
Very easy, made with a toddler and still successful!
Made this delicious tray bake last week for my granddaughter’s birthday, we all loved it, the all in one method is easy to follow and turned out great, easily cut into a good 2 shape ,
Making it again today .
This looks lovely. What do you mean by espresso powder though please? Is that instant espresso coffee?
Hi – yes that’s what I mean (although it is optional) x
Should the oven temperature be reduced if using a fan oven, or is 170 deg for fan oven? Thanks
Yes reduce to 160
Hi Lucy, Sam again 🙂 I want to scale up this cake (as it’s so good) for my son’s birthday party, into a 12×16″ tray and keep the depth. I’ve attempted the calculations and failed miserably 🙂 so would you please be able to advise what % increase I should apply to the current ingredient list to make the larger size, and what increase in baking time I should anticipate please? Many thanks for your awesome recipes!!
Hi Sam – I have done some calculations here but since I haven’t tested this I am not 100% sure it is right. I would suggest you double the recipe and use as much batter as you need and then bake cupcakes with any leftover.
If you want to try my calculations, see below
450g flour plain / all purpose
90g unsweetened cocoa powder
450 g sugar use half granulated, half light brown if you like
1 1/2 tbsp espresso powder (optional)
1 1/2 tbsp baking powder
½ tbsp bicarbonate of soda
½ tsp salt
300 g unsalted butter or Stork softened
4 large eggs
270 ml whole milk
2 tbsp lemon juice to sour milk
Chocolate Frosting
390 g icing sugar
8 tbsp unsweetened cocoa powder
225g softened unsalted butter
180 ml (½ cup) milk slightly warm
260g dark chocolate chips melted and cooled
Hi Lucy, thanks so much for your reply. I decided to try a 160% increase on the base recipe and it appears to have worked perfectly, so so pleased! I made a test one last night and cooked it for an extra 5/10 minutes, and it looked so good I have just made another one to layer up 🙂 Thanks again, looking forward to trying out some more of your recipes xx
I don’t normally leave comments but I have to say this worked perfectly and my children love it. They don’t like icing so I left the cake plain, it was a great hit, everything worked in the recipe. Will try more from this site as that’s a rare occurrence I find!! Thanks Supergoldenbakes 🙂
What a wonderful comment you made my day ❤️❤️❤️
May I use milk chocolate chips instead of dark for the frosting? I would like to make this for my little sisters birthday and she’s not really a big fan of dark chocolate?
You can but it may be too sweet. Maybe use half milk and half dark?