This simple one layer chocolate cake is made in a 9x13-inch pan and topped with the best chocolate sour cream frosting! This single-layer chocolate cake is super moist and soft thanks to buttermilk and neutral oil. This chocolate sheet cake doesn't require any fancy equipment or decorating skills! It's perfect with sprinkles and I think it's the best birthday cake!
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I love my chocolate cake recipes (hello Matilda's chocolate cake!), but I was getting questions and comments about how to turn my chocolate cake with vanilla frosting into a sheet cake.
I used my tried-and-tested chocolate cake recipe and baked it in a 9x13-inch pan, and presto - the perfect chocolate buttermilk sheet cake! I think this would be great for birthday parties, potlucks, bake sales, or a holiday party (hello, just change the color of the sprinkles depending on the holiday!) where you need to serve a bunch of people.
If you want a vanilla sheet cake, try my chocolate chip vanilla sheet cake recipe! It actually uses the same frosting, too! What I love about a sheet cake is that you don't need fancy frosting skills, you don't need tools like a piping bag or a turntable to frost your cakes. This is just a good old-fashioned sheet cake, which is going to taste great (and hey, it looks pretty cute too).
Grab Your Ingredients!
- Cocoa Powder: Make sure you're using Dutch-processed cocoa powder and not natural cocoa powder. They react differently to baking powder and baking soda, so they aren't always interchangeable. Not sure what you've got? Check the ingredients! If it says 'alkali' or 'acidity regulators', it's Dutch-processed.
- Neutral Oil: Using oil instead of melted butter makes our cake soft and moist for DAYS, people! Use an oil like vegetable, canola, or sunflower. We want something without a strong flavor or smell.
- Buttermilk: Using buttermilk in this chocolate sheet cake will give it a slight tang and make it super moist. Cocoa powder can make baked goods dry, so using an ingredient like buttermilk will help keep the cake moist.
Let's Make This Sheet Cake!
- Step 1: Preheat the oven and line a 9-x13-inch baking pan with parchment paper. Whisk the dry ingredients together in a large bowl.
- Step 2: Add all the wet ingredients except for the hot water. Mix until smooth.
- Step 3: Slowly pour in the hot water and whisk. There is a LOT of cake batter and it is very liquidy!
- Step 4: Pour the cake batter into the prepared pan. Bake in the oven. Let cool completely and then frost!
Different Frostings
If you don't want the chocolate on chocolate, here are a few frostings you can use instead!
- Vanilla Frosting - a classic!
- Biscoff Frosting - cookie butter and chocolate? Sign me up.
- Cream Cheese Frosting - ok, you guys, this would be SO good.
- Mint Frosting - it's giving Thin Mints!
- Oreo Frosting - for those cookies and cream vibes.
Made This Recipe?
Make sure to leave a ⭐️ rating and review below! You can tag me on Instagram @alpineella or follow along on Pinterest, Facebook and TikTok!
Thank you!
Ella
Recipe
One Layer Chocolate Cake (Sheet Cake)
Equipment
- 1 9x13-inch cake pan
Ingredients
Chocolate Cake
- ¾ cup (65 grams) cocoa powder dutch processed
- 1 ¾ cups (350 grams) granulated sugar
- ¾ teaspoon (¾ teaspoon) vanilla extract
- ¾ teaspoon (¾ teaspoon) kosher salt
- 2 (2) eggs room temperature
- 2 cups (220 grams) all purpose flour
- 2 teaspoon (2 teaspoons) baking soda
- 1 teaspoon (1 teaspoon) baking powder
- 1 cup (240 ml) buttermilk room temperature
- ½ cup (120 ml) vegetable oil
- 1 cups (240 ml) very hot water
Chocolate Sour Cream Frosting
- ½ cup (110 grams) unsalted butter room temperature
- pinch (pinch) kosher salt
- 1 cup (113 grams) confectioners' sugar
- ½ cup (42 grams) cocoa powder dutch processed
- ¼ cup (60 ml) sour cream room temperature
- 3 oz (85 grams) dark chocolate chopped
Instructions
Make Cake
- Preheat your oven to 350°F/175°C. Butter or grease a 9x13-inch cake pan and then line with parchment paper. I recommend making a 'sling', so you have parchment paper overhanging, to make it easier to get the cake out!
- Combine the flour, cocoa powder, sugar, baking powder, baking soda, and salt in a large bowl with a whisk.¾ cup (65 grams) cocoa powder, 1 ¾ cups (350 grams) granulated sugar, 2 cups (220 grams) all purpose flour, 2 teaspoon (2 teaspoons) baking soda, 1 teaspoon baking powder, ¾ teaspoon kosher salt
- In a large jug, whisk together the buttermilk, oil, eggs, and vanilla extract.¾ teaspoon vanilla extract, 1 cup (240 ml) buttermilk, ½ cup (120 ml) vegetable oil, 2 eggs
- Slowly pour in the ingredients from the large jug and mix until just combined.
- Slowly add the hot water and mix. Your batter will be very thin and it makes a lot of cake batter!1 cups (240 ml) very hot water
- Pour the batter into the prepared pans. Bake for 35-40 minutes, until a toothpick comes out clean when inserted
- Allow the cakes to cool for 10 minutes before removing from the pan. Let them cool completely on a cooling rack.
Make Frosting
- Melt your chocolate in a microwave, stirring every 10 seconds so it doesn't burn.3 oz (85 grams) dark chocolate
- In your stand mixer with the paddle attachment, or in a bowl with a handheld mixer, beat the butter and confectioners' sugar on low speed until well combined½ cup (110 grams) unsalted butter, 1 cup (113 grams) confectioners' sugar
- Turn the speed to high for 2-3 minutes until light and fluffy.
- Add in your cocoa powder and beat on low, then increase the speed to medium for 1-2 minutes.½ cup (42 grams) cocoa powder
- Add your sour cream, melted chocolate and salt and mix once more.¼ cup (60 ml) sour cream, 3 oz (85 grams) dark chocolate, pinch kosher salt
- Frost your cooled cake and enjoy!
Save This Recipe! 💌
I'll email this recipe to you, so you can come back to it later!
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