This chocolate sheet cake is a must-have recipe for so many reasons. First, it’s incredibly delicious—seriously, it might just be one of the best chocolate cakes out there. Second, it’s made in just one pot, so you won’t end up with a kitchen disaster. And third, sheet cakes are the ultimate crowd-pleasers and are super easy to transport—much more convenient than cupcakes! 🎉
Three Frosting Options:
- Chocolate Buttercream
- Pourable Fudgy Icing
- Cookies and Cream Buttercream
A special thanks to my friend Jess, who inspired this simplified version of my classic chocolate cake recipe. While my original recipe is quite the showstopper, Jess pointed out that having a quicker and easier option would be perfect for home cooks needing a delicious dessert on short notice or when baking for a large group. She was right—this one-pot sheet cake hits all the marks!
Why This Recipe Works
With this recipe, you don’t need a mixer, a double boiler, or a bunch of dirty dishes. All it takes is one pot, a few minutes of prep, and just 20 minutes of baking time. The result? A rich, moist, and irresistibly delicious chocolate cake! 🍰✨
Perfect for Any Occasion
Because it’s a sheet cake, it’s easy to slice, serve, and transport, making it perfect for gatherings, potlucks, and celebrations. I’ve slightly adjusted the proportions of the original recipe to fit the larger baking surface, resulting in a thinner cake that bakes evenly and stays wonderfully moist.
Choose Your Icing
I’m offering two classic icing options to top this chocolatey goodness:
- Chocolate Buttercream: A tried-and-true favorite that’s creamy and luscious.
- Pourable Fudgy Icing: Quick, easy, and perfect for pouring over a warm cake. No need to wait for the cake to cool completely—just pour and let it set!
No matter which one you choose, you’re guaranteed a cake that’s moist, gooey, and packed with chocolate flavor. So, grab your pot, gather your ingredients, and let’s get baking! 🍫💫
No buttermilk? No problem. Put 2 tsp of white vinegar or fresh lemon juice in your 1/2 cup measure. Fill the rest with milk. Allow it to sit at room temperature for 10 minutes to thicken and turn into "homemade buttermilk"
Preheat oven to 350.
Line large rimmed baking sheet with parchment paper, allow the sides of the parchment to overhang so that the cake could be easily lifted out after it's baked. I'm using 13x18 half sheet, which is ideal for this cake. But regular jelly roll rimmed baking sheet will work.
Melt butter over low heat in a medium pot. Once melted, remove from heat.
Add chopped chocolate and allow to sit for a minute. Then stir with a rubber spatula until chocolate has melted. Add cocoa powder and stir more until smooth.
Mix in coffee, sugar, salt and vanilla with a whisk.
You do not need to let this mixture cool completely, however, allowing it to cool down a little bit is a good idea.
Add buttermilk and eggs, making sure to whisk well immediately after adding, to gradually warm the eggs and ensure they do not scramble in your still warm chocolate mixture.
Sift flour combined with baking powder and baking soda directly into your batter. Mix it with a whisk until completely combined. Then mix with a few more vigorous strokes of a whisk to aerate the batter a bit.
Pour into prepared baking sheet. Bake in preheated oven for about 20 minutes until the cake is firm and a toothpick inserted in the centre comes out with just a few crumbs but not wet/liquid batter. If you press down on the cake, your finger should still be able to leave an indentation, a sure sign your cake is plenty gooey and not overbaked.
The internal temperature measure that I love to use with baking will not work as well here, since the cake is so thin and the reading may not be accurate – toothpick will work just fine!
Remove the cake from the oven and allow to cook completely before icing.
In a bowl of a stand mixer, mix all of the icing ingredients on low at first (to avoid all of the sugar and cocoa from splashing everywhere.) When everything is incorporated, increase the speed to high and beat for a few minutes until fluffy and lightened in colour. Remember to adjust consistency of the buttercream with more heavy cream, if needed. Stop the mixer, scrape the sides of the bowl and beat on high for another minute or two.
Lift the cooled cake out of the pan by the sides of the parchment paper. Spread 2/3 of the buttercream evenly over cake. Pipe the remainder of the icing in a decorative manner, if desired.
Slice the cake into desired number of squares, I sliced into 32.
Ingredients
Directions
Preheat oven to 350.
Line large rimmed baking sheet with parchment paper, allow the sides of the parchment to overhang so that the cake could be easily lifted out after it's baked. I'm using 13x18 half sheet, which is ideal for this cake. But regular jelly roll rimmed baking sheet will work.
Melt butter over low heat in a medium pot. Once melted, remove from heat.
Add chopped chocolate and allow to sit for a minute. Then stir with a rubber spatula until chocolate has melted. Add cocoa powder and stir more until smooth.
Mix in coffee, sugar, salt and vanilla with a whisk.
You do not need to let this mixture cool completely, however, allowing it to cool down a little bit is a good idea.
Add buttermilk and eggs, making sure to whisk well immediately after adding, to gradually warm the eggs and ensure they do not scramble in your still warm chocolate mixture.
Sift flour combined with baking powder and baking soda directly into your batter. Mix it with a whisk until completely combined. Then mix with a few more vigorous strokes of a whisk to aerate the batter a bit.
Pour into prepared baking sheet. Bake in preheated oven for about 20 minutes until the cake is firm and a toothpick inserted in the centre comes out with just a few crumbs but not wet/liquid batter. If you press down on the cake, your finger should still be able to leave an indentation, a sure sign your cake is plenty gooey and not overbaked.
The internal temperature measure that I love to use with baking will not work as well here, since the cake is so thin and the reading may not be accurate – toothpick will work just fine!
Remove the cake from the oven and allow to cook completely before icing.
In a bowl of a stand mixer, mix all of the icing ingredients on low at first (to avoid all of the sugar and cocoa from splashing everywhere.) When everything is incorporated, increase the speed to high and beat for a few minutes until fluffy and lightened in colour. Remember to adjust consistency of the buttercream with more heavy cream, if needed. Stop the mixer, scrape the sides of the bowl and beat on high for another minute or two.
Lift the cooled cake out of the pan by the sides of the parchment paper. Spread 2/3 of the buttercream evenly over cake. Pipe the remainder of the icing in a decorative manner, if desired.
Slice the cake into desired number of squares, I sliced into 32.
Notes
Variation for thick fudgy pourable icing. You can make this instead of the buttercream:
In a medium sauce pan, melt 14 TBSP of unsalted butter over low heat; remove from heat once melted. Add heaping 1/4 cup of cocoa powder and stir. Stir until it forms into thick ganache-looking concoction. Add 1/4 tsp kosher salt, 6 TBSP milk, 1 tsp vanilla and 3 cups powdered sugar. Whisk well to combine. The consistency should be thick but pourable; if your icing is too thin, you may need to add a bit more powdered sugar. Pour over your cooled or still warm sheet cake. Feel free to add chopped toasted walnuts or pecans for another layer of textures and flavours. It’s so delicious!
Variation for the Cookies and Cream buttercream:
200 g shortcake cookies (lotus biscoff ideally, but replace with regular ones if cannot locate) – that’s around 2/3 of a standard box
11 tbsp butter, unsalted at room temp
1 ¾ cups icing sugar
1 tsp vanilla
pinch of kosher salt
3 tbsp heavy cream, plus more if needed
Crush your cookies in a blender, food processor or place them with a resealable plastic bag and smash with a rolling pin. Add butter, sugar, crushed cookies, pinch of salt, vanilla and 2 TBSP cream to a bowl of your stand mixer. Mix on low to incorporate, then turn to medium high and beat until the mixture is light and fluffy, for 3-5 minutes. Be sure to stop the mixer and scrape up the sides of the bowl. Add a bit more cream to adjust consistency, if needed.
This is literally one of the best recipes I’ve tried so far.
The cake is excellent, it’s sweet, moist and chocolatey.
It’s easy and simple yet super delicious!
Thank you for sharing!
Thanks so much M. I’ve been working on this recipe for sooooooooo long xoxo
This recipe is genius! By far the easiest homemade cake I have ever made! Currently making for my second time to cure my chocolate craving for the next few days
Aww Lauren, thanks so much hun!!! “Genius” – I love that word to describe this cake! So happy you enjoyed! xoxo