CAKE:

1 stick butter
4 tbsp. cocoa (unsweetened)
1 tsp. vinegar
1 c. water
1/2 c. buttermilk
2 c. flour
2 c. sugar
1 tsp. baking soda
1/2 tsp. salt
2 eggs
1 tsp. vanilla

ICING:

1 stick butter
4 tbsp. cocoa
1/3 c. buttermilk
1 lb. confectioners' sugar

In a large bowl sift together the cocoa, flour, sugar, baking soda and salt. Set aside. In a medium saucepan, bring water, butter and vinegar to boil. Add hot mixture to dry ingredients. Add eggs, vanilla and buttermilk. Beat at low speed scraping bowl. Pour into an ungreased jelly roll pan and bake at 375 degrees for 20 minutes. Batter will be thin.

Icing: Bring butter, cocoa and buttermilk to a gentle boil. Remove from heat. Add confectioners' sugar. Frost cake still warm.