Homemade Chocolate Sheet Cake with Boiled Chocolate Frosting

pile of three pieces of cake with a bite taken out of the top piece

Homemade Chocolate Sheet Cake with Boiled Chocolate Frosting

A deliciously rich homemade chocolate sheet cake with a boiled chocolate frosting. This is a classic chocolate sheet cake recipe can also be known as Texas Chocolate Sheet Cake.

Course Dessert

Cuisine American

Prep Time 30

Cook Time 22

cooling time 1

Total Time 1 52

Servings servings

Calories 324kcal

Author Susie Weinrich

Equipment

18x12x1 Sheet Pan

Ingredients

Chocolate Sheet Cake

2 cups All Purpose Flour
2 cups Sugar
1 teaspoon Kosher Salt
1 cup Butter (salted or unsalted)
1 cup Water
3 tablespoon (heaping) Cocoa
2 Eggs
½ cup buttermilk See notes
1 teaspoon Baking Soda
1 teaspoon vanilla

Chocolate Frosting

1 cup Butter
3 tablespoon Cocoa
5 tablespoon Milk
1 teaspoon Vanilla
3 ½ cups Powdered Sugar

Instructions

Prep

Preheat the oven to 350°F. Prepare a large sheet pan (18x12x1) by greasing.
If you are using sour milk method- combine ½ cup milk with 2 tablespoon white vinegar and set aside. If you are using buttermilk you can skip this step.

Chocolate Sheet Cake

In a large bowl combine flour, sugar and salt. Set aside.
2 cups All Purpose Flour, 2 cups Sugar, 1 tsp Kosher Salt
In a saucepan over medium high heat bring to a boil 1 cup butter, 1 cup water, and 3 Tablespoons cocoa.
Remove from heat and stir into the flour/sugar mixture.
1 cup Butter, 1 cup Water, 3 Tbsp (heaping) Cocoa
Next add 2 slightly beaten eggs (you may want to temper your eggs slightly with a tablespoon of the warm batter ), ½ cup sour milk, 1 teaspoon baking soda, and 1 teaspoon vanilla. Stir to combine.
2 Eggs, ½ cup buttermilk, 1 tsp Baking Soda, 1 tsp vanilla
Pour into prepared sheet pan. Bake for 18-20 minutes.
While the cake is baking prepare your frosting so it can be poured on as soon as the cake comes out of the oven.

Boiled Chocolate Frosting

In a saucepan over low heat mix together butter, cocoa powder, milk, and vanilla.
1 cup Butter, 3 Tbsp Cocoa, 5 Tbsp Milk, 1 tsp Vanilla
Stir until it is melted and then add the 3 ½ cups powdered sugar. Stir until it is well combined.
3 ½ cups Powdered Sugar

Assembly & Storing

As soon as the cake comes out of the oven pour the frosting over the cake. Smooth with a offset spatula or knife. Let rest 1 hour for the frosting to set before serving.
Store at room temp, covered, for up to a week.

Notes

Sour Milk or Buttermilk:

Either will work in this recipe.

If you do not have buttermilk you can make your own by combining ½ cup milk with 2 tablespoon white vinegar, let it sit for a few minutes and then give it a stir.

Nutrition