Texas Sheet Cake

Cake:

2 cups flour
2 cups sugar
1 tsp. soda
½ tsp. salt
1 cup water
1 cup butter
4 heaping Tbsp. Cocoa
2 eggs beaten
½ cup sour cream
1 tsp. vanilla

Mix together flour, sugar, soda and salt. 
In a saucepan bring to boil water, butter and cocoa.  Stir this into flour Mixture.
Add eggs, sour cream, and vanilla.
Pour into greased and floured sheet pan 15½" x 10½".  Bake at 350° for 20 minutes.
The frosting then gets spread onto this hot cake.

Frosting:

½ cup butter
6 Tbsp. milk
4 Tbsp. cocoa
1 tsp. vanilla
1 cup chopped walnuts (optional)
1 lb. powdered sugar

Bring butter, milk and cocoa to a bubbly boil.  Remove from heat and add powdered sugar, vanilla and nuts.  Frost cake while quite warm.