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
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Hey Jane,
I attempted this last night and although the cake is moist and tastes amazing, it sunk in the middle and just falls to bit when you try and pick it up. What have I done wrong and how can I fix it for next time? Thank you! X
If it sunk in the middle it probably wasn’t quite finished baking – the cake is very delicate as well but that’s part of its delicious charm! x
These look amazing and I can’t wait to make. My mums coeliac so as usual for us they’ll be gf. Have you made this traybake gf before? Can’t decide between these and some of your other gf recipes! I know you’ve quite recently given up gluten so if need any hints or tips on the best products etc then let me know. Xxx
Hiya – I haven’t recently given up gluten, I still eat it! You could definitely try it GF however, but I haven’t with this one in particular. You would need to add in xantham gum to stabilise the mixture before, but it will most likely be extremely soft without the gluten so beware!
Hi, can you tell me if i can use an alternative to the buttermilk? I cant have dairy ( i can adapt everything else) didn’t know if i can use almond milk instead? thanks.
I’m afraid I am unsure of a dairy alternative to buttermilk – I would advise looking at a dairy free cake such as mine and covert that into a traybake!
i think u can use any other dairy free milk and add vinegar to make a buttermilk substitute
Hello!
Can you tell me how deep the cake tin needs to be? Thank you!
Hiya! I think mine is 2-2.5″ deep! Most traybake size tins are similar! x
Hi Jane, please could you tell me what the oven temperature is for this delicious cake? My cake seemed to come out a little raw 🙁 still lovely though!
Its 160C, or 140C for a fan oven – as mentioned, it can take longer for some ovens to bake the cake. If it’s raw, it wasn’t finished baking.
I often find that the supermarket traybakes are quite dry, so i’m definitely trying this! I just found your website and it has given me so many ideas x
I hope you love it! X
Hii,
I’m not really a fan of dark chocolate (too strong)
Can I use milk Chocolate instead?
You can’t taste it once it’s baked into the cake, I would only use dark chocolate. It makes it delicious, and it’s not too dark after.
I tried this today and was very excited but something has gone wrong. I opened my oven after 40mins and my cake seems as though it has sunk but the middle section is crispy. Do you have an idea what I have done wrong 😞
I think you opened the oven too early, so it sunk and baked weirdly. The temperature can change up to 10 degrees for every second the oven is open, so if it was too early for the bake it would have affected it quite badly!
Hi Jane,
This is the first recipe I’ve made from your blog and I think I will have to try lots more! It was absolutely beautiful and I got so many compliments on it. My frosting was a lot paler than yours, I wonder if I did anything wrong? But it tasted amazing anyway
It was probably down to the cocoa powder – which one did you use? x
All I had was some from Lidl, that was probably it! Thanks x
Sometimes some just aren’t as dark or as chocolatey! I use Tescos own, and it looks so much darker than bournville for example! xx
This was amazing thank you Jane! Made if for 2 work colleagues leaving today & added smarties & maltesers for decoration – just incase there wasn’t enough chocolate already lol! Loads of posititve comments from my work mates & not much left when I left mid afternoon!
Any chance you could do a recipe for a similar traybake but with no chocolate (or white chocolate) as my husband gets migranes from milk & plain chocolate & missed out on the deliciousness! Thanks a million
Hiya! I have other recipes scheduled in, but I don’t like post similar recipes like this too close together so it is coming! But I’m glad this one was enjoyed!!
Hi – loving your blog. Think you might want to check your U.S. conversions from Metric on this recipe as they seem all over the place e.g. sugar, coffee, and bicarb.
It’s all done automatically, I don’t do the conversions myself.
Can I cut out one of the sugars as in just put 250g instead of 500?
I wouldn’t advise it – to get what’s in the pictures, you need to use the recipe.
cake looks good but i t drink coffee so i wont go get coffee to make this cake. i can tell there something different when added coffee/ cuz friend made cupcakes using coffee and i could tell theres a different in taste.
I completely disagree as I don’t drink coffee at all as I’m really not a fan, and I can’t taste it in this, but that’s up to you. x
Hey! Love you recipes. Can you just confirm the cooking time please. In the intro it says 35 mins and then 50-60 in the instructions? Thank you xx
Ooh it appears it calculated it wrong haha! It’s the 50-60. x
Fab! I have a dodgey oven anyway so will take as long as it takes haha. Will make sure to tag you on Instagram! Thank you
Hahaha mine used to be so I know what you mean!! Enjoy!
Does this recipe really use 500g of sugar or is it a misprint? It seems rather a lot.
500g is correct. As you get so many slices from it, it’s not that much per portion.
Thank you. I went ahead and made it and I must say, it’s one of the most delicious chocolate cakes I’ve tasted…….my husband has even requested it instead of an actual cake for his 40th birthday in November! Thank you for sharing your wonderful recipes, I haven’t found one yet that hasn’t been amazing! 😊
Ahh amazing!!!
How deep was the tin you used?
Hi what brand of dark chocolate do you use?
It can really range, but most often or not its supermarket own basic dark chocolate! X