Description
The Denver Chocolate Sheet Cake is a rich, moist chocolate cake baked in a single pan and topped with a luscious, fudgy cocoa frosting. Made with Dutch cocoa, buttermilk, and a hint of vanilla, this classic American dessert is perfect for gatherings or any occasion that calls for a chocolate treat. Optional chopped walnuts or pecans add a delightful crunch to the smooth and creamy frosting.
Ingredients
For the Cake:
- 2-1/2 cups all-purpose flour (plus extra for pan)
- 2 cups granulated sugar
- 1 teaspoon baking soda
- 1/4 teaspoon salt
- 2 sticks unsalted butter, cubed (plus extra for pan)
- 1/2 cup Dutch cocoa powder, sifted
- 1 ½ cups water
- 1/2 cup buttermilk
- 2 eggs, lightly beaten
- 1 ½ teaspoons vanilla extract
For the Frosting:
- 1 stick unsalted butter
- 1/2 cup Dutch cocoa powder, sifted
- 6 tablespoons buttermilk
- 1 teaspoon vanilla extract
- 1/4 teaspoon salt
- 3 ½ cups powdered sugar
- 1/2 cup chopped walnuts or pecans (optional)
Instructions
- Preheat and Prepare Dry Ingredients: Preheat your oven to 350˚F. In a large bowl, combine 2-1/2 cups all-purpose flour, 2 cups granulated sugar, 1 teaspoon baking soda, and 1/4 teaspoon salt. Set this mixture aside.
- Make Cocoa Mixture for Cake: In a small saucepan over medium-low heat, add 2 sticks cubed unsalted butter, 1/2 cup Dutch cocoa powder, and 1 ½ cups water. Whisk constantly until the butter is melted and the cocoa is fully incorporated. Remove from heat.
- Combine Batter: Pour the warm cocoa-butter mixture into the dry ingredients. Stir just until combined. Then, add 1/2 cup buttermilk, 2 lightly beaten eggs, and 1 ½ teaspoons vanilla extract. Stir gently until the batter is smooth and even.
- Prepare Baking Pan and Bake: Grease and flour a 9”x13” cake pan. Pour the batter evenly into the pan. Bake in the preheated oven for 28-32 minutes, or until a toothpick inserted in the center comes out clean. Remove the cake from oven and let it cool completely.
- Prepare Frosting: In a small saucepan over medium-low heat, melt 1 stick unsalted butter. Add 1/2 cup Dutch cocoa powder and 6 tablespoons buttermilk, stirring constantly with a whisk. Cook for about 1 minute until the mixture reaches the consistency of a thin pudding. Remove from heat.
- Finish Frosting and Apply: Stir in 1 teaspoon vanilla extract, 1/4 teaspoon salt, and 3 ½ cups powdered sugar quickly into the warm cocoa mixture until smooth and glossy. Pour this warm frosting evenly over the cooled cake.
- Add Nuts and Set: Before the frosting sets, sprinkle with 1/2 cup chopped walnuts or pecans if desired. Allow the frosting to set for at least 1 hour at room temperature before cutting.
- Serve: Cut the cake into 15 squares and serve. Enjoy the rich, moist chocolate flavor with a fudgy, nutty finish!
Notes
- Ensure cake is completely cooled before adding frosting for best texture.
- Chopped nuts are optional but provide a nice crunchy contrast.
- Use Dutch cocoa powder for a richer, deeper chocolate flavor.
- You can substitute regular milk for buttermilk with 1 tablespoon vinegar or lemon juice per 1/2 cup milk as a buttermilk substitute.
- Store leftover cake covered at room temperature for up to 3 days or refrigerate.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
