Texas Sheet Cake

2 c. sugar
2 c. flour
1 c. butter
4 T. cocoa
1 c. water
½ c. buttermilk
2 eggs, beaten
1 t. vanilla
½ c. chopped walnuts
1 t. baking soda

Frosting:
½ c.  butter
4 T. cocoa
6 T. milk
1 lb. powdered sugar
1 t. vanilla
1 c. chopped pecans

Sift together sugar and flour.  Bring butter, cocoa, and water to a boil.  Pour liquid mixture over flour and sugar mixture and stir.  Add buttermilk, eggs, vanilla, walnuts, and baking soda.  Mix well and pour on a greased cookie sheet.  Bake at 400° for 20 minutes.  
Frosting:  combine butter, cocoa, and milk in saucepan.  Bring to boil.  Add powdered sugar, vanilla, and nuts.  Mix well and spread over cake.