Chocolate Cake Traybake!
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Thick chocolate cake traybake, with thick chocolate frosting! Perfect for parties, or occasions, or anything!
Traybake cakes
I haven’t done too many traybake recipes in my time, if you talk about cake style traybakes. The other side, the brownies, blondies, rocky roads etc I have done almost too many to count (whether the recipes made it to the blog or not), but cake wise? Only a few. This is for any particular reason to be honest, just because I never thought they were very ‘wow’.
To be fair, I am completely wrong. I often get requests for a cake like this, and I just haven’t really got round to it until now! When I posted my carrot cake traybake in March, it was SUCH a big hit! I honestly didn’t expect it, and it was a bit of a random one to plug some days up in the run up to Easter, but I regret not posting it sooner!
Requested recipe
I thought originally “oh its just a cake that you give out at a party, if you don’t want the centrepiece cake too big”, which is actually often a thing. People create a ‘cutting cake’ if they don’t want, or can’t have the actual wedding cake for example that massive. I just didn’t realise that people like making them at home so much!
When I have asked in the past for requests of recipes, I usually get really out there ones that are almost a bit too specific for my blog, or ones that I have done, or ones that I would happily do. But quite often or not, there are ones that are just basic bakes that I have managed to have not done already, or ones that completely passed my mind like this one!
Sponge
When starting this recipe I wanted to make sure that it was going to be delicious. When you have a traybake cake, there is NO WHERE to hide. You can’t layer it up and make it look that pretty, and its so big that its awkward to try and cover up in some way. I wanted to make sure that the cake was suitably fudgey, and delicious, like the ‘traybake cakes’ that you can buy for parties in the supermarket.
You can easily do it with a straight forward Victoria sponge style sponge but I just think if you really are only leaving it as is, with some frosting on top, then I wanted it a smidge denser to make it more delicious. I ended up basing it on my chocolate fudge cake recipe, but slightly altered to fit the tin better!
Coffee and buttermilk
Because this sponge uses coffee, and buttermilk, it creates the most wonderful thick gooey sponge that everyone wants to devour. Trust me, YOU CAN’T TASTE THE COFFEE, and it just enhances the chocolate flavour so I would 100000% recommend sticking with it! Honestly, you’ll regret it if you don’t. You can use actual espresso, or instant coffee etc, but anything dissolved in 125ml of water will do.
Frosting and decoration
The Frosting for the cake is also from my chocolate fudge cake recipe, as its just personally the best chocolate frosting on the planet ever. This is optional, you could easily use just melted chocolate, or a ganache type frosting, but I really wanted a good solid frosting instead that is usually a crowd pleaser, and from the comments I have received in the past, this is the frosting to choose! You can decorate it how you want, but I just went for some sprinkles and some small chocolate bits and it’s all done! Cut up into squares and enjoy! x
Chocolate Sheet Cake!
Ingredients
Cake
- 250 g dark chocolate
- 250 g unsalted butter
- 1 tbsp instant coffee
- 125 ml boiling water
- 200 g plain flour
- 50 g cocoa powder
- 1.5 tsp baking powder
- 1/2 tsp bicarbonate of soda
- 250 g caster sugar
- 250 g light brown sugar
- 4 large eggs
- 100 ml buttermilk
Frosting
- 250 g unsalted butter (room temp)
- 500 g icing sugar
- 50 g cocoa powder
- 100-125 ml evaporated milk
- 1 tsp vanilla extract
Extras
- Sprinkles
- Chocolate curls
Instructions
For the Cake
- Preheat your oven to 160/140C Fan, and line a 9x13" tin with parchment paper.
- In a heatproof bowl, microwave the dark chocolate & butter until melted – mine takes two minutes!
- Pour the coffee granules into 125ml boiling water and mix – add the coffee to the chocolate/butter mix and stir well until smooth!
- In a separate large bowl add the plain flour, cocoa powder, baking powder, bicarbonate of soda, golden caster sugar, and light brown sugar and mix well so the ingredients are all mixed with each other well!
- Mix the eggs with the buttermilk – add the chocolate mix & the egg mix to the dry ingredients and stir together, try not to over mix it – you don't need to use an electric mixer, just use a bowl and a spatula.
- Pour the mixture into the tin and bake in the oven for 50-60 minutes (can take a little longer in some ovens) once baked leave to cool in the tin and remove afterwards, or leave for 10-15 minutes and cool on a wire rack for a softer cake.
For the Frosting
- With an electric mixer with the paddle attachment, beat the butter until its very smooth and supple (couple of minutes)
- Gradually add the icing sugar & cocoa powder alternatively with the evaporated milk until all is incorporated and add the vanilla essence – beat for a couple of minutes so its extra smooth & creamy.
- The more evaporated milk you add the more runny it’ll be, and I have found about 100ml-125ml is perfect for me! Decorate your cake how you like and ENJOY!
Notes
- This cake will last for 3 days at room temperature.
- This is the cake tin I used
- I 100% would stick with using the coffee in the cake, you can't taste it, but it helps the chocolate flavour so is important.
- The cake can take longer to bake if its over mixed - be as gentle as possible with it.
- If you can't access buttermilk, you can make your own by using 100ml of FULL FAT milk, mixed with 2tbsp of lemon juice! It will look curdled but this is fine.
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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.
Hi! This cake was AMAZING! Could I also maybe make it as a 9inch round cake? Maybe make it twice, put some buttercream in the centre to stack? Thanks 🙂
Made this yesterday and it was delicious! I did struggle to cut the cake cleanly though, so you have any tips?
Lovely cake, tastes delicious. Mine did sink in the middle but this hasn’t stopped it being so good! I can’t work out why mine sank as I followed the recipe to the letter…. Apart from the chocolate, I used milk chocolate as I couldn’t find dark chocolate where I am….but it seems to have worked! I will make it again…. Hopefully with dark chocolate, and see if it sinks again, maybe my raising agents were not measured correctly?
The chocolate will likely be the reason it has sunk, but also too much raising agent will make it rise and then collapse xx
Hi, I was wondering how come there is 500 grams of sugar in the cake mix ( half brown half white) Shouldnt this be 250 g Maximum compared to the other quantities? I am going to make this for our twins birthday. Thank you Jane.
Hiya – no, the measurements are correct. This is a fudge cake recipe, not a standard basic chocolate cake x
This is one of the best chocolate cake recipes I’ve tried! Absolutely lovely! The one question I had is can I freeze the cake with the icing already on it? The cake is quite large and I don’t want it to go to waste so wondered whether you can freeze the cake already decorated? Thanks!
Yes definitely! I would portion the cake, freeze the pieces on a chopping board until solid and then freeze in a container (so that the icing doesn’t squish) x
Hello, I’m excited to make this for my daughter’s birthday cake. I have 3 questions:
1. As the kids are young I don’t want to use coffee (although personally would love it) – is there any alternative?
2. If making it the day before should I leave it in the fridge overnight or just out?
3. My tin is 13x15inch – do you think I need to increase the recipe or just reduce cooking time?
Thanks!
Can I top this with chantilly cream? Thought it’d be a bit different! But would it be okay stored in the fridge?
I want to make a rocket ship shaped cake for my grandson’s birthday. Will this be suitable to cut to shape? Should I free before trying to cut the shapes out? Can you crumb coat whilst it’s still frozen? Thanks
This is quite soft, the chocolate school cake sponge would be better!
Hi planning to make this recipe for my husband’s birthday this weekend. Can I ask what % cocoa solids chocolate you’ve used?
Also could it be halved and stacked on top as a sandwich or is it a delicate crumb?
Thanks in advance!