My easy chocolate sheet cake is basically perfect. So fluffy and FULL of chocolate flavor, without being oily and sad like so many store bought cakes. A nice dollop of fudge transforms this buttercream into something almost magical but if you don’t have any handy try adding in some ganache!
What You’ll Need for this Recipe
For the Buttercream: You can either make a simple ganache by melting chocolate and cream, or you can use a nice runny fudge. In the recipe video I used fudge but have heard from many of you that finding the right type of fudge can be a bit tricky so if in doubt just make a ganache!
Buttermilk: I love using buttermilk in cakes but it’s not something you always have on hand so feel free to either use some buttermilk powder OR sour some milk with lemon juice or white vinegar. About a tablespoon or either mixed into a cup or milk will do the trick.
How to make Chocolate Sheet Cake
1. Preheat the oven to 350F and line a 9×12 cake pan with parchment paper. Sift the flour, baking soda, baking powder, salt, sugar and cocoa powder together into a large bowl then whisk to combine.
2. In a medium bowl add the sour cream, buttermilk, eggs, vegetable oil, and vanilla. Whisk together then mix in the hot coffee.
3. Pour the wet ingredients in with the dry and whisk to combine. Mix on low for about a minute and scrape the bowl down.
4. Transfer batter into your prepared pan and bake for about 50 minutes or until a toothpick inserted in the center comes out clean. Allow to cool for a few minutes then invert onto a wire rack and peel parchment paper off.
5. For the frosting; cream the butter in a stand mixer, add the salt and cocoa powder then mix on low until combined. Scrape the bowl down then beat in the confectioners sugar. Once your mixture has come together you can scrape the bowl down and add the fudge or cooled ganache. Mix until silky and smooth. If things are a bit stiff you can add milk or cream a tablespoon at a time until desired consistency is reached.
6. Time for the assembly! Add the buttercream to the top of the cake with an ice cream scooper. Spread and smooth with an offset spatula. You can decorate the cake with sprinkles, chopped toasted nuts or shaved chocolate. Enjoy!
There’s something so comforting about a sheet cake. It is totally low stress baking that delivers all the taste!
Pro Tips for This Recipe
- Use whole milk with a tablespoon of vinegar or lemon juice as a substitute for the buttermilk.
- Measure your flour correctly! Adding too much flour to the recipe is the most common mistake. The best, and easiest way to measure flour is by using a scale. If you don’t have one then fluff your flour with a spoon, sprinkle it into your measuring cup, and use a knife to level it off.
- You can substitute whole milk yogurt for the sour cream if desired, I do it all the time and can’t really tell the difference.
- Hate coffee? Just use warm water instead!
- If You Don’t Have Fudge Handy just whip up a quick ganache. Scald 1/4 cup of cream or milk and pour over an equal amount or semi or bittersweet chocolate chips (or chopped). Let it sit for a few minutes then whisk together. You can add more or less of this into the buttercream It’s really up to you!
Frequently Asked Questions
How many does this serve?
A 9″ x 13″ pan will yield about 30 2″x2″ pieces.
An 18” x 26″ pan will yield about 78 2″x2″ pieces.
Can you freeze it?
You can freeze a sheet cake for the ultimate make ahead treat. For best results freeze the cake unwrapped then once frozen, wrap well and store for up to 3 months. You may also want to freeze the cake and frosting separately. This way the moisture in the buttercream will not seep into the cake.
What’s the difference between sheet cake and regular cake?
Sheet cakes are one layer of, usually rectangular, cake topped with buttercream. Layer cakes are two or more layers with frosting in between. Layer cakes are quicker to assemble and can feed large groups.
If you love this recipe try these out!
If you’ve tried this chocolate sheet cake then don’t forget to leave a rating and let me know how you got on in the comments below, I love hearing from you!
The Best Chocolate Sheet Cake
Video
Ingredients
For the Cake
- 1/2 cup sour cream 115g
- 1 cup buttermilk 236mL
- 3 large eggs
- 1 1/2 cup coffee 354mL, strong and hot
- 3/4 cup vegetable oil 177mL
- 1 tablespoon vanilla extract 15mL
- 3 cup all-purpose flour 360g
- 2 2/3 cup granulated sugar 530g
- 1/2 cup cocoa powder 50g
- 1 1/2 teaspoon baking powder 6g
- 1 tablespoon baking soda 18g
- 3/4 teaspoon kosher salt 4g
For the Frosting:
- 1 1/2 cups unsalted butter 330g
- ½ cup cocoa powder 50g
- 3/4 teaspoon salt 4g
- 1 pound confectioners sugar 453g, sifted
- ⅓ cup fudge 100g OR ganache
Instructions
For the Cake:
- Preheat to 350 degrees. Line a 9x13 inch cake pan with parchment.
- Sift together the flour, sugar, salt, baking soda, baking powder and cocoa powder into a large bowl and whisk to combine.
- Add the sour cream, buttermilk, eggs, vanilla, and vegetable oil into a medium bowl and whisk together then pour in the coffee and mix once more.
- Add the wet ingredients to the dry ingredient bowl.
- Whisk to combine then mix on low for about a minute.
- Pour batter into the lined pan. Bake for about 50 minutes or until a toothpick inserted in the center comes out clean.
- Allow to cool for a few minutes then invert onto wire rack. Peel parchment paper off and let cool fully.
For the Frosting:
- If you're using a nice runny fudge then have that ready. If you don't have that on hand then melt about 1/4 cup milk or cream with 1/4 cup dark chocolate, mix to combine then set aside to cool. Cream butter in a stand mixer fitted with a paddle attachment. Beat in cocoa powder and salt and mix until combined.
- Add the confectioners sugar in a few batches mixing in on low. Scrape the bowl down and mix once more.
- Add fudge or ganache in and mix until well combined. You can add milk or cream in a tablespoon at a time to thin the consistency out If needed.
For the Assembly:
- Add buttercream to the top of the cake with an ice cream scooper. Spread over with an offset spatula.
- Decorate with sprinkles, chopped toasted nuts or shaved chocolate
Notes
If You Don't Have Fudge Handy
If you're substituting the fudge for a ganache just scald 1/4 cup of cream or milk and pour over an equal amount or semi or bittersweet chocolate chips (or chopped). Let it sit for a few minutes then whisk together. You can add more or less of this into the buttercream It's really up to you!TIPS AND POINTERS:
- Use whole milk with a tablespoon of vinegar or lemon juice as a substitute for the buttermilk.
- You can substitute whole milk yogurt for the sour cream if desired, I do it all the time and can’t really tell the difference.
- Hate coffee? Just use warm water instead!
Nutrition
Wow! Have tried countless chocolate cake recipes off the internet, and this one–well, takes the cake! Made exactly as listed, and it came out perfect. We cut two eight-inch circles out of the 9 x 13 pan and were able to make two double-layered mini cakes with lots of leftovers for cake pops or just snacking. Thank you for the recipe!
Hi John. Your page is my new favorite go to for all recipes. Love everything.. My question is can this recipe be used for cupcakes? 😃🧁
I can’t believe how good this cake is!!! My wife doesn’t like any chocolate cake, but everything I’ve made with your recipe has been outstanding so when I made this she gave it a try. Turns out she LOVES chocolate cake when it’s done right… So much so she begged me to make another one this weekend, and this time she swears she not sharing even a bite with the kids… Thanks, John!
Hi, John! I LOVE your recipes. I have won some prizes for my baking over the years … I’ve been baking for some 50 years of my life … I am now retired and baking more than I ever have due to the COVID Pandemic precautions … my husband and I have avoided eating store-made food due to COVID, since the COVID shutdown began in March 2020 … So, now, I’ve been baking everything from breads to cakes, cookies, and desserts, for the last 5 months or so. I have been meaning to ask some well-known Pastry Chefs, such as you, WHY DO CAKE RECIPES THAT CALL FOR OIL DON’T JUST USE CLARIFIED BUTTER? Nowadays, Clarified Butter is available almost everywhere with the huge populations of East Indians here in North America … we live in a suburb of Toronto, Canada. I find that using CLARIFIED BUTTER in a cake recipe, produces a very buttery soft crumb, and an amazing butter flavor. But I have also found that you need to use just a tiny amount LESS of the Clarified Butter than the amount of oil in the cake recipe because the Clarified Butter tends to be a little heavier than most oils. Also – could you please give your ingredient amounts in WEIGHT, in a recipe, as well as in volume (which you do)? … I find that when I make Ganache it’s better to know the WEIGHT of the chocolate rather than the volume such as 1/2 cup … in your Best Chocolate Sheet Cake recipe, you have mentioned making Ganache using 1/2 cup heavy cream and 1/2 cup chocolate chips … BUT I PREFER TO USE COUVERTURE Chocolate, and NOT chocolate chips to make my Ganache. BTW – I HAVE A B.Sc. degree in Math. BLESSINGS … Sheila J.
It’s really because the oil will stay moist and soft even when the cake is chilled.
I am from bangladesh and I always follow your recipe.I have tried your profiteroles and other recipes.I have a dream to be like you sir.All the very best and stay safe.
Would this recipe work for cupcakes?
I made this cake and it was delicious!
Love, Love, Love the chocolate sheet cake recipe. Think there is a small typo …
WHAT’S THE DIFFERENCE BETWEEN SHEET CAKE AND REGULAR CAKE?
Sheet cakes are one layer of, usually rectangular, cake topped with buttercream. Layer cakes are two or more layers with frosting in between. Layer cakes are quicker to assemble and can feed large groups
Layer cakes are quicker and easier than sheet cakes??
Thank you for the recipe, this is THE chocolate cake I will make from now on because it comes out a lot flatter than all the other recipes I have tried. My kids said ” Mummy this cake recipe is IT, your search is over.” So that says a lot about this cake.
I usually use 2/3 of the recipe and make it in an 8×8 square pan, with whipped chocolate ganache on top.
We are in love with this cake!!!
So my son requested a chocolate Blaze theme cake for his 6th bday; I came across this recipe And this is my first time baking sheet cake, I’m in awe how good this cake is. Our guests loved it even the picky eaters had a slice. Thank you. Easy no fuss and great for beginners.