Chocolate sheet cake is filled with rich chocolate flavor. Each slice has a sweet, tender crumb and is topped with chocolate buttercream frosting!

square slice of chocolate sheet cake next to rest of cake with chocolate buttercream frosting

Chocolate on chocolate is the best way to enjoy cake. This chocolate sheet cake is perfectly sweet and has a soft, tender crumb. The cake is incredibly easy to make from scratch and the velvety chocolate buttercream is simply irresistible!

Why this recipe works: The chocolate sheet cake is simple, yet flavorful. The chocolate flavor comes from good quality cocoa powder. Milk complements the cocoa while creating a tender crumb. The recipe can be made into two 9-inch rounds or 18 cupcakes.

chocolate sheet cake ingredients labeled with text

Overview: How to make chocolate sheet cake

  1. Preheat oven to 350 F. Grease a 9×13 cake pan.
  2. Whisk together dry ingredients—flour, cocoa powder, espresso, baking soda and salt. Set aside.
  3. Mix together wet ingredients—milk and vanilla. Set aside.
  4. Beat butter and sugar together until light and fluffy. Add eggs one at a time.
  5. Alternate adding dry and wet ingredients to the batter. Mix just until combined. Transfer batter to prepared pan.
  6. Bake cake for 25 to 30 minutes or until a toothpick inserted in the center comes out clean. Let cake cool completely.
  7. Make chocolate butter cream frosting. Beat butter until light and fluffy. Sift confectioners’ sugar and cocoa into butter and beat until combined. Add vanilla and milk. Mix until smooth.
  8. Frost cake with an offset spatula and serve.
photo collage demonstrating how to make chocolate sheet cake in a mixing bowl
chocolate sheet cake with chocolate frosting garnished with sugared cranberries and rosemary sprigs for christmas

Helpful tips for making chocolate cake

There are a few rules to follow when making cake. First, weigh your ingredients. Cake is a delicate dessert and measurements have to be exact. If you don’t have a kitchen scale, be sure to fluff and spoon your flour into the cup (rather than using the measuring cup to scoop the flour).

Use room temperature ingredients. This helps the consistency of desserts, especially cake. The batter mixes more evenly! Use good quality unsweetened cocoa powder for better chocolate flavor. I prefer Ghirardelli premium unsweetened cocoa powder. Add espresso powder. It has the same flavor profile as chocolate. When just a little bit of espresso powder is added to any chocolate dessert, the chocolate flavor becomes richer without making the cake taste like coffee.

My last tip, or rather trick, is to use my magic cake pan release. The cake will release out of the pan without any trouble! That way you can frost the bottom or flat side of the cake.

square slice of chocolate cake on plate with fork taking a bite from the cake

Frequently Asked Questions

How to store chocolate sheet cake:

Cover cake or store in an airtight container. Keep it at room temperature for 2 days or in the refrigerator for 5 days.

Can you freeze chocolate sheet cake?

Yes. Once the cake has completely cooled, remove it from the pan and securely wrap it in plastic wrap then aluminum foil. Store on a flat surface in the freezer for up to 1 month. Defrost in the refrigerator before bringing to room temperature and frosting.

How to make a chocolate cake moist:

Use whole milk and make sure the milk is room temperature. I find that buttermilk makes the cake tart and sour cream makes cake too dense. Whole milk works best for normal chocolate cake. Also, avoid over baking the cake. A cake is done when a toothpick inserted in the center comes out with little to no crumbs on it.

How to decorate chocolate cake:

Sprinkles are my favorite option, but you can also add fresh strawberries, raspberries and blueberries. Another idea is using a stencil and dusting powdered sugar on top to create a design. During the holidays I enjoy making sugared cranberries and adding sprigs of rosemary to the cake.

I love a good chocolate cake. This recipe is very similar to my chocolate cupcake recipe, which is also topped with the same chocolate buttercream frosting! If you prefer a denser cake, check out my chocolate pound cake recipe topped with chocolate ganache. My favorite gluten-free version of cake is flourless chocolate cake.

slice of chocolate sheet cake with chocolate frosting on a round plate next to forks and offset spatula

Chocolate sheet cake is a simple dessert that is enjoyed by anyone who likes chocolate. The cake is easy to make from scratch and pairs well with many frostings, but chocolate buttercream is my favorite! What occasion will you be making this cake for? Let me see on social media! Tag @ifyougiveablondeakitchen and I will share my favorites on Instagram.​​​​​​​

chocolate sheet cake square with chocolate frosting

Chocolate Sheet Cake

Chocolate sheet cake is filled with rich chocolate flavor. Each slice has a sweet, tender crumb and is topped with chocolate buttercream frosting!

Ingredients

Chocolate Sheet Cake

  • 1 ¼ cups (156 g) all purpose flour
  • ½ cup (48 g) unsweetened cocoa powder
  • 1 teaspoon espresso powder, coffee powder works too
  • ½ teaspoon salt
  • ½ teaspoon baking soda
  • 1 cup plus 2 Tablespoons (270 mL) whole milk, , room temperature
  • 1 teaspoon pure vanilla extract
  • 12 Tablespoons (170 g) unsalted butter,, room temperature
  • 1 ¼ cups (250 g) granulated sugar
  • 2 large eggs,, room temperature

Chocolate Buttercream Frosting

  • 1 cup (226 g) unsalted butter,, room temperature
  • 2 cups (240 g) confectioners' sugar
  • ½ cup (48 g) unsweetened cocoa powder
  • 1 teaspoon pure vanilla extract
  • 2-3 Tablespoons milk

Instructions 

Chocolate Sheet Cake

  • Preheat oven to 350° F. Grease and flour a 9×13 cake pan.
  • In a medium bowl, whisk together flour, cocoa powder, espresso, baking soda and salt. Set aside.
  • In a measuring cup, stir together milk and vanilla. Set aside.
  • In the bowl of a stand mixer or using a hand mixer, beat butter on high speed until light in color, about 1 minute. Add sugar and mix on high until fluffy, about 2 to 3 minutes. Add eggs one at a time mixing well after each addition.
  • Alternate adding flour mixture and milk to the batter. Add one third of the flour mixture, followed by half of the milk mixture. Repeat and end with remaining flour mixture. Mix just until combined and scrape down the sides and bottom of the bowl as necessary.
  • Transfer batter to prepare pan and evenly spread it to the corners of the pan. Bake for 22 to 26 minutes or until a toothpick inserted in the center comes out with little to no crumbs. Let cake cool completely before frosting.

Chocolate Buttercream Frosting

  • Using an electric mixer, beat butter until light and fluffy, about 2 minutes. Place confectioners' sugar and cocoa in a mesh strainer or sifter and sift over the butter. Beat until combined. Add vanilla and 2 Tablespoons milk. Mix until smooth. Add more milk if you'd like a thinner consistency.
  • Transfer frosting to the cooled cake. Use an offset spatula to spread the frosting over the cake. Cut and serve.

Notes

Store chocolate sheet cake covered at room temperature for 2 days or in the refrigerator for 5 days.
Freeze chocolate sheet cake (unfrosted) in a layer of plastic wrap, then aluminum foil. Store on a flat surface in the freezer for up to 1 month. Defrost in the refrigerator before bringing to room temperature and frosting.
High altitude adjustments: Decrease sugar by 1/4 cup. Replace espresso powder with 1 Tablespoon espresso or strongly brewed coffee. Increase oven temperature to 360 F. Decrease baking time to 20 to 24 minutes.
Serving: 1slice, Calories: 388kcal, Carbohydrates: 45g, Protein: 4g, Fat: 23g, Saturated Fat: 15g, Cholesterol: 80mg, Sodium: 135mg, Potassium: 139mg, Fiber: 2g, Sugar: 33g, Vitamin A: 716IU, Calcium: 39mg, Iron: 1mg

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