Texas Sheet Cake

3/4 lb butter (3 sticks)
4 TBS cocoa
1 Cup water
2 Cups flour
2 Cups sugar
1/2 Cup buttermilk
2 eggs
1 tsp baking soda
1 tsp vanilla
Icing:
1/2 Cup butter
4 TBS cocoa
6 TBS milk
1 pound powdered sugar
1-1 1/2 Cups pecan chopped
1 tsp vanilla

Melt and bring to boil butter, cocoa and water.  Sift together flour and sugar.  Pour hot mixture into sugar mixture then add buttermilk, eggs, baking soda and vanilla.  mix well.  Prepare pan by spraying with PAM.  Pour into long cookie sheet with sides and bake at 375 for 20 minutes.  Prepare icing while cake bakes.  In sauce pan bring to boil butter, cocoa, and milk; add powdered sugar and beat in; add pecans and vanilla.  Pour over cake as soon as it comes out of the oven.  Let cook and serve.