The ultimate dark chocolate traybake topped with incredibly smooth and utterly delicious buttercream. This is the only chocolate cake recipe you will ever need to satisfy all of your chocolate cravings!

Hey folks! Hope you all are well and having a great week! Last few weeks have been incredibly busy for me, and the next few are looking pretty much the same. But... I couldn't wait any longer with sharing this recipe with you, because it is simply too damn good to be missing out on it!
Dark Chocolate Traybake with Buttercream Frosting
Honestly, this traybake guys... I think it is safe to say, this is THE one. I first saw this beauty on my friend Heather's blog. Heather is a genius when it comes to baked goodies, and when I saw her posting a picture of this 'snack cake' it instantly blew me away.
Beautiful, moist and rich chocolate sponge topped with silky-smooth, heavenly buttercream. I mean...who on earth would say no to this?!?
When I first baked it, we ate a whole tray almost immediately. NOT KIDDING. I then baked it again, and to prevent the same thing happening (us demolishing the whole thing again), I gave it away to my neighbours. They've confirmed what we already knew, it was the best chocolate cake they've ever had!
Ingredients to make this bake
This recipe will produce enough batter for 2 8-inch square bakes, but I also made it in a bigger, rectangular baking tin (12 x 8 inch). Any leftover batter can be baked into cupcakes or a smaller cake.
I have followed Heather's recipe almost exactly, but had to substitute couple of ingredients, purely because I did not have them on hand. Canola oil, which the original recipe called for have been replaced by olive oil. I have also replaced the espresso powder with a cup of strong, freshly brewed coffee, and bittersweet chocolate chips with dark chocolate.
The sponge ingredients
To make the sponge, you will need few, simple ingredients, but try to stick to high quality ones, as this will produce the best ever results! Staring with dark chocolate. Use the best quality you can get. Minimum 70% cocoa solids. I've used Lindt dark chocolate.
You will also need a cup of hot, strong and freshly brewed coffee. Because adding coffee will enhance the flavour of cocoa and chocolate, resulting in a more chocolatey cake. And don't worry, you will not taste coffee in your traybake! You will also need Greek yogurt, olive oil, milk, two large eggs and one extra egg yolk, vanilla, plain flour, golden caster sugar, good cocoa powder (Dutch processed), baking soda, baking powder and salt.
Buttercream ingredients
To make this super, silky smooth, heavenly buttercream, you will only need 5 ingredients. Softened butter, some more dark chocolate (same as above), icing sugar, vanilla and salt. This buttercream is a dream to work with, the texture is super soft, light, fluffy and spreadable. It can be used on different cakes and bakes too, so make a note of it!
Instructions for making dark chocolate traybake
As with any bake, start with heating your oven to the right temperature and prepare your baking tray/ tins.
Place chopped, dark chocolate in a medium bowl and pour hot, freshly brewed coffee over it. Cover with some clingfilm and set it aside, allowing it to melt slowly.
After that, mix the 'wet' ingredients together. Both eggs and an extra egg yolk, yogurt, milk, olive oil and vanilla.
Place all of the dry ingredients in a bowl of your standing mixer fitted with paddle attachment and mix on low speed until they are combined. Slowly add the yogurt mix into the bowl with dry ingredients, followed by the mix of coffee and chocolate. Make sure to keep scraping the bottom and the sides of your bowl, to ensure all of the ingredients are well incorporated.
Pour the batter into prepared baking tray and bake for 25- 30 minutes, until toothpick inserted in the middle comes out clean. It took about 22 minutes in my fan-assisted oven at 160C.
Cool the cake for about 10 minutes, then remove it from the tin and transfer to a wire rack to cool completely. If you try to add your buttercream while the cake is still warm, you will end up with a melted mess.
Final touch- spread that heavenly buttercream on top!
Make the buttercream while the cake is cooling. Simply whip the butter, add vanilla and salt, followed by icing sugar and melted dark chocolate.
Spread it using a spatula or a back of the spoon on top of the cake creating little swirls, if you desire.
Honestly, I think this is the best part of making this chocolate traybake. It is almost hypnotic and oddly satisfying to play with that buttercream. Once you've done it, you will know what I mean!
Slice the cake into little squares, and share the joy, but nobody will judge you if you decide to keep it all to yourself!
If you enjoyed this chocolate traybake recipe, make sure to check out this recipe for Chocolate Brownies with PB Frosting too!
As always, thanks for reading today's post! Feel free to leave me a comment and a rating below, I would love to hear from you!
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📖 Recipe
Dark Chocolate Traybake
Equipment
- 2 x 8 inch square cake tins
Ingredients
- 100 g dark chocolate ( min 70% cocoa solids) chopped
- 250 ml hot, freshly brewed, strong coffee
- 120 ml Greek yogurt
- 120 ml olive oil
- 120 ml milk
- 2 large eggs plus one egg yolk
- 1 ½ teaspoon vanilla
- 270 g all purpose flour
- 365 g caster sugar
- 75 g Dutch processed cocoa (I used Green & Black organic cocoa powder)
- 2 teaspoon baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
For the buttercream:
- 200 g dark chocolate (min 70% cocoa solids) chopped
- 340 g unsalted butter softened
- 1 teaspoon vanilla
- ¼ teaspoon salt
- 270 g icing sugar
Instructions
- Pre heat the oven to 175 C ( 160 C fan). Lightly grease two 8- inch square cake tins and line them up with baking parchment.
- Place 100 g chopped dark chocolate in a heatproof bowl and pour the hot, freshly brewed coffee over it. Cover the bowl with clingfilm and set aside.
- In a medium bowl, combine together yogurt, olive oil, milk, eggs and vanilla. Whisk to combine and set aside.
- In a bowl of a standing mixer, fitted with paddle attachment, mix together flour, sugar, cocoa, baking soda, baking powder and salt on a low speed until combined.
- With the mixer still running on the low speed, slowly add the yogurt mixture. Mix on medium speed for 30 seconds, until well combined.
- Stir the chocolate and coffee mixture until smooth. Slowly pour this mixture into the rest of the batter, mix on low speed until incorporated.
- Remove the bowl from the mixer and scrape down the sides with spatula, ensuring that everything is well combined, but don't over mix it. Pour the batter into prepared cake tins and spread it evenly in the tin.
- Bake for 25-30 minutes or until toothpick inserted in the middle comes out clean. It's OK if there is a bit of crumb remaining.
- Remove from the oven, allow the cakes to cool for about 10 minutes, then transfer the cakes into a cooling rack and allow them to cool completely before frosting it.
To make buttercream:
- Melt the dark chocolate in a heatproof bowl set over a pan of simmering water, stirring it constantly. Once melted, remove from the heat and cool slightly.
- In a bowl of a standing mixer, fitted with the paddle attachment, cream the butter on a medium high speed for 3 minutes, until pale and fluffy.
- Add the vanilla and salt and beat on medium speed until incorporated. Reduce the speed to low, and carefully add the icing sugar.
- Once combined, increase the speed to medium high and beat until smooth and silky, about 3 minutes. Make sure to scrape the sides of the bowl from time to time. Add melted chocolate to the sugar and butter mixture, mix on low speed until fully combined.
- Frost the cooled cake with the buttercream and enjoy!
Please note that all my recipes are developed and tested in metric grams. I recommend that you use digital scales for a more accurate results. I have provided a conversion to US customary in the recipe but please note that I haven’t tested using this method.
Angel says
Hi Anna,
Just wanted to know if I can just opt to use one-8 inch square pan to bake this? I like high cakes so, was thinking if I can make it in a single batch and frost it… can it fit into an 8x8x2 square pan if baked in a single batch? Thanks in advance! Merry Christmas to u!
annabanana says
Hi Angel, I would highly recommend to stick to two smaller baking pans and perhaps freeze one of them for later. If you really want to bake it in one, the baking time will have to be adjusted, the cake will need longer in the oven. You may have to cover the top of the cake with some kitchen foil if it starts catching too much. Hope this helps! And merry Christmas to you too!
Michelle says
This looks soooo delicious! That frosting looks so light and creamy. I want to make this for my birthday next week.
annabanana says
Hello Michelle! It would be an ideal birthday cake, it's easy enough to make it but never fails to impress! Also, perfect for sharing! Happy Birthday and enjoy the cake!
Sam | Ahead of Thyme says
OMG I need a slice (or 10) of this chocolate cake. It looks so rich and dense, and that frosting.. wow! Can't wait to try this.
annabanana says
Hey Sam, so happy that you will be trying it out, and I can definitely tell you that you will not stop at one slice!
Jamie says
This was such a decadent cake. I love how you added coffee and yogurt in this cake. Delicious!
annabanana says
Thanks so much Jamie! So happy to hear that you've enjoyed this cake! Happy days!
Amanda says
Oh my this looks so decadent and your photos are STUNNING 🙂
annabanana says
Hey Amanda! Thanks so much for your sweet comment! So happy you like it!
Jenni LeBaron says
This traybake cake looks so delicious! I love dark chocolate so this has my name on it. That frosting also looks perfect!
annabanana says
Glad you like it Jenni, thanks so much! I hope you will bake it soon! x
Linda says
I love anything dark chocolate and this one looks so wonderful and so moist!
annabanana says
Same here Linda, dark chocolate is my weak spot! This cake would be right up your street if you are also a fan! Hugs!
Colleen says
Yes! This is what chocolate cake dreams are made of. Just the real, classic perfection of deep dark chocolate, moist,and with a perfect crumb.. Great recipe. Thanks for sharing!
annabanana says
Glad you like it Colleen, it really is the ultimate chocolate cake! And pleasure all mine!
Analida Braeger says
Scratch baking is the only way to go and I love the coffee flavor in this cake! Thanks for sharing!
annabanana says
Thanks so much Analida! Coffee is actually added to enhance the chocolate flavour, but you will not taste it in this cake at all.
Patti says
This recipe looks amazing. Coffee always makes chocolate taste better, and I am drooling on my tablet screen over all of that luscious butter cream. I agree with you about the hypnotic effects of buttercream. Frosting cakes and chopping vegetables are two things that I find relaxing
I have one request. If you are going to be making any more chocolate goodies. can you send me your address, so I can move into the neighborhood and become a taste tester? I’m a really good taste tester. 😉
annabanana says
Haha, Patti, I will be more than happy to have you as my taste tester! And yes, I find spreading buttercream or kneading the dough are the most satisfying kitchen activities!Thank you so much for stopping by!
Shelley says
Oh my goodness, I could just dive into that frosting! What a gorgeous, alluring cake! And, I'm excited that it subs out the espresso powder (which I never have on hand) for strong, freshly brewed dark coffee (which I ALWAYS have on hand)! I'm just gonna bet that your neighbors wish you needed to do a couple more tests on this cake, huh?!?! (And yeah ... I'm kind of wishing I was one of those lucky neighbors!) 😉
annabanana says
Hey Shelly, thanks so much for your lovely comment. This frosting is really something, isn't it? I could easily eat it on its own! And I would love for us to be neighbours 😉