A rich, moist chocolate cake baked in a sheet pan and topped with a smooth, fudgy chocolate frosting. This classic dessert has a soft, tender crumb and deep chocolate flavor in every bite.

Ingredients

Cake
2 cups all-purpose flour
2 cups sugar
1 teaspoon baking soda
1/2 teaspoon salt
1 cup butter
1 cup water
1/4 cup unsweetened cocoa powder
1/2 cup buttermilk
2 large eggs
1 teaspoon vanilla extract
Chocolate Frosting
1/2 cup butter
1/4 cup unsweetened cocoa powder
6 tablespoons milk
1 teaspoon vanilla extract
3 1/2 cups powdered sugar

Directions

Step 1 – Prepare the Pan
Preheat oven to 350°F (175°C).
Grease a 13 x 18-inch sheet pan (or similar jelly-roll pan).
Step 2 – Make the Cake Batter
In a large bowl, combine flour, sugar, baking soda, and salt.
In a saucepan, bring butter, water, and cocoa powder to a gentle boil.
Pour the hot cocoa mixture over the dry ingredients and stir until combined.
Add buttermilk, eggs, and vanilla.
Mix until smooth.
Step 3 – Bake
Pour batter into the prepared pan.
Bake for 18–22 minutes, or until a toothpick inserted in the center comes out clean.
Step 4 – Make the Frosting
While the cake is baking, melt butter in a saucepan.
Stir in cocoa powder and milk.
Remove from heat and add vanilla.
Gradually whisk in powdered sugar until smooth.
Step 5 – Frost the Cake
Pour warm frosting over the warm cake immediately after removing it from the oven.
Spread evenly with a spatula.
Allow frosting to set before serving.

Recipe Card Photo