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
Lynda says
Just made this today and it’s PERFECT. And almost as easy as a store-bought mix. Thank you John!
John Kanell says
Wonderful to hear!
Sharon says
Hi John, just wanting to know what temperature the coffee should be – boiling hot?
jkanell says
doesn’t have to be boiling, hot to warm is fine
Natasha B says
My husband is VERY picky when it comes to sweets (he’s not a huge fan of sweets) but I really wanted to try this and it’s a HUGE hit in my house! My kids (obviously) love it and so does my husband so thank you!
Jennie Hardware says
Hi John, i‘ve Made this recipe a few times now and ai just love it. I LOVE all your recipes. I would love it if you did a vanilla sheet cake recipe some time as well ?. All the best, Jennie from @sweetsndreamscakes.
Lydia Fernandes says
Hi John,
I made your sheet cake recipe for my son’s 1st birthday and it was exceptional
Ive been told by everyone who ate the cake that it was super moist.. though i changed the frosting from buttercream ti ganache. The cake still was very good.
Thank you
Lydia Fernandes
Claire Haynes-Simmons says
Hi John what size pan did you use
jkanell says
this was a 9×13 inch pan
Christine Raniga says
If you want to make this in a mega 18×26, do you need to double the recipe?
jkanell says
This recipe makes a 1/4 sheet cake which is 9×13. It sounds like you would quadruple the recipe.
Manisha says
Hi John,
Thanks for the recipe! I substituted eggs for water and it still worked great for me.
Izza says
Hi John,
Thank you for sharing an amazing sheet cake
Wanna asking…
What is that fudge you used?…
Any other substitute for it?
jkanell says
Hello! I forgot the brand but you could sub in some chocolate ganache!
Tiffany says
I made the chocolate cake today for hot fudge cake. Excellent, great, fantastic! The coffee makes it more than just a chocolate cake. The batter smelled terrific and tasted better (totally taste tested too much). It is an easy recipe to make no need for a box mix. Will try it with the buttercream next time. Thanks for the great recipes!
John K. says
Hi Tiffany,
I’m glad you enjoyed this recipe!
I agree, I find that coffee only increases the chocolate flavor.
I hope you enjoy the buttercream when you get a chance to try it. 🙂
Happy baking!
John
Mary says
Is there a way to make this recipe into a layer cake?
John Kanell says
check out my chocolate layer cake!
Ashley says
love love love, absolutely the best chocolate cake recipe. I used this for a bday cake and it turned out amazing; First time hit and everyone loved it! Thank you again for posting your delicious recipes!! Keep them coming!!
Durre says
Hi John
This is the first time I have used your website and a recipe of yours. I made the sheet cake today and although it is delicious most of the middle is dense and not fluffy like the outside. It baked completely (tested with skewer) and even rose high in the middle when I took it out (but went back to normal height when cooled.) I just don’t understand why it was so stodgy in the middle. Only the sides were baked perfectly. Any ideas?
Also credit where credit is due, you are such a lovely person and I love watching your videos, your positivity and smile shines through the screen. You really are great to watch. Hope you can help me with this issue as I’d love to make it again!
Love from London UK
jkanell says
Thanks so much! I saw your post on Insta!I think the cake was not done. Sounds like the center was under-baked.