Texas Sheet Cake II

1 C butter
1 C water
1/4 C unsweetened cocoa
2 C flour

2 C sugar

2 eggs

1/2 C sour cream

1 tsp. baking soda

Icing:

1/2 C butter

1/4 C unsweetened cocoa

6T milk

2 C confectioner's sugar

1 tsp. vanilla

1 C chopped nuts

For the Cake:Place the first 3 ingredients in a large saucepan and bring to a boil over medium low heat. Remove from the heat, and add the next 3 ingredients. Beat in the eggs, sour cream and baking soda. Pour into a greased jelly roll pan(15X10). Bake at 350 degrees for 20 minutes. Cool completely before icing. For the icing:in a large saucepan, bring the first 3 ingredients to a slow boil. Remove from the heat, and sift in the confectioners sugar beating until smooth and thick. Add the vanilla and spread over the cooled cake. Sprinkle on nuts if desired.