Just in case you don't have the recipe, I'm posting it. I've been making this version nearly all my life. Have used tbe buttermilk recipe but I prefer the one with sour cream. There is a White Texas Chocolate Sheet Cake, also, which I will post next. Wonderful cakes!

This cake disappears FAST!

Texas Sheet Cake is made with sour cream and cocoa and a frosting with chopped pecans.

INGREDIENTS:
1 cup butter
1 cup water
1/4 cup cocoa
2 cups sugar
2 cups flour
1/8 teaspoon salt
2 eggs
1 teaspoon baking soda
1/2 cup sour cream
1 teaspoon vanilla
Frosting, below
chopped pecans

PREPARATION:
Frosting
1/2 cup butter
1/4 cup cocoa
1/4 cup plus 2 tablespoons milk
1 box (1 pound) confectioners' sugar, sifted (4 1/4 cups sifted)
1/2 teaspoon vanilla

Cake: Combine butter, water, and cocoa in saucepan over medium heat; heat until butter melts. Add sugar, flour, salt, eggs, soda, sour cream, and vanilla; mix well. Pour into a 15x10x1-inch jelly roll pan. Bake at 350° for 20 minutes. Spread frosting over hot cake and sprinkle with chopped pecans.
For frosting, combine butter, cocoa, and milk in a saucepan; bring to a boil. Add remaining ingredients and mix well with electric mixer. Spread over the hot sheet cake then sprinkle with chopped pecans.