Chocolate Sheet Cake

Chocolate 13x18 sheet cake slice served on a plate.

Chocolate sheet cake is a moist and tender homemade cake with rich chocolate flavor. The velvety whipped chocolate buttercream frosting makes it perfect for chocolate lovers! This recipe can be made in a 9x13 or 13x18 pan.

Prep Time 20

Cook Time 20

Resting Time 1

Total Time 1 40

Servings or more servings

Author Heather

Ingredients

Chocolate cake

1 ¾ cups (210 g) all-purpose flour
¾ cup (63 g) natural cocoa powder
2 teaspoons baking soda
1 teaspoon baking powder
½ teaspoon salt
1 ¾ cups (345 g) granulated sugar
3 large eggs room temperature
1 cup (227 g) buttermilk
1 cup (226 g) warm water
½ cup (100 g) vegetable oil
2 teaspoons vanilla extract

Whipped chocolate buttercream frosting

1 cup (227 g) unsalted butter room temperature
3 cups (342 g) confectioner's sugar
½ cup (42 g) natural cocoa powder
⅓ cup (75 g) heavy cream cold
2 teaspoons vanilla extract
¼ teaspoon salt

Instructions

Cake

Preheat oven to 350℉. Generously grease a 9x13 or 13x18 inch baking pan and set aside.
In a bowl, add flour, cocoa powder, baking soda, baking powder, and salt. Sift or whisk to remove clumps. Set aside.
In a large bowl, add granulated sugar, eggs, buttermilk, warm water, vegetable oil, and vanilla extract. Whisk or stir until evenly incorporated.
Add half of the dry ingredients to the wet ingredients. Gently stir until just combined. Add remaining dry ingredients and stir until just combined (do not overmix). Batter should look thin and a little bubbly.
Pour batter into prepared baking pan.
9x13 baking pan: 32-38 minutes
13x18 half sheet pan: 18-20 minutes
Bake your cake using the time frames above as a reference. To test for doneness, gently press into the center of your cake with a finger. If it bounces back, it's done. If it leaves an indent, the cake needs more time. Use an instant read thermometer for exact results. Cake is done when it reaches 210F in the center.
Remove cake from oven and allow to cool completely in the pan on a wire cooling rack.

Frosting

In a large bowl, add room temperature butter. Using a hand mixer or stand mixer, beat until creamy (about a minute). Gradually add confectioner's sugar and cocoa powder and mix slowly until ingredients are fully combined. Then, whip at high speed for about 2-3 minutes, or until light and fluffy.
Add heavy cream, vanilla extract, and salt. Whip for an additional 2-3 minutes, or until light and fluffy. Add additional heavy cream as needed to reach desired consistency.
Spread frosting in an even layer onto cooled cake. Optionally, add sprinkles before frosting crusts.

Video

Notes

Servings: Sheet cake can be sliced to serve up to 24 guests.
Science: Baking is an exact science. I do not recommend substituting any ingredients. The oil, buttermilk, eggs, and sugar keep your cake moist - substituting any of these ingredients can change the texture and make your cake dry.
Storage: Unfrosted or frosted cake will keep in a sealed container at room temperature for 2-3 days, in the refrigerator for 3-4 days, or frozen for up to 2 months. If refrigerating or freezing unfrosted cake layers, wrap tightly in plastic and place in a tightly sealed container. Thaw overnight in the refrigerator, then bring to room temperature for an hour before serving.
Tips: Be sure to check out my 10 tips for baking cake, based on reader comments and questions!

Nutrition