Texas Sheet Cake

Boil Together:
3/4 cup butter, softened
3/4 cup shortening, softened
1/3 cup cocoa
1 1/2 cups water

Pour Over:
3 cups flour
3 cups flour

Add:
3/4 cups buttermilk (milk with 1 1/2 Tbsps vinegar)
1 1/2 tsp baking soda
1 1/2 tsp vanilla
3 eggs, beaten
1/4 tsp salt

Directions:
Mix together butter, shortening, cocoa, and water; bring to boil.
Pour over flour and sugar, which have been sifted together. Mix well.
Add buttermilk, soda vanilla, eggs and salt. Mix well.
Bake for 20 minutes at 400 degrees F in a well greased and floured large cookie sheet.
5 minutes before the cake is done, prepare frosting.

Frosting:
1/2 cup butter
1/4 cup cocoa
1 tsp vanilla
6 Tbsps milk
4 cups powdered sugar
1 cup chopped pecans or walnuts (optional)

Melt butter: add cocoa, vanilla, and milk. Bring to a boil. Remove from heat and add powdered sugar and nuts. Mix well. Frost cake while hot.