Sift 2 cups flour into a bowl with 2 cups of sugar.
Mix in a sauce pan 1 stick margarine, 1/2 cup shortening, 4 Tablespoons cocoa unsweetened powder,1 cup water.dry ingredients.
Bring to a boil then pour over dry ingredients. Mix well then add: 1/2 cup sour milk, 1 teaspoon baking soda, 2 eggs, 1 teaspoon cinnamon, 1 teaspoon vanilla.
Mix well then pour over well buttered , floured large sheet cake pan 1 inch deep. Bake 20 minutes at 400 degree's. I sometimes use powdered unsweetened cocoa instead of flour to coat the pan.
Icing: Bring just to a boil, 1 stick margarine, 4 Tablespoons cocoa unsweetened powder, 4-6 Tablespoons milk, 1 pound powder sugar, then add 1 teaspoon vanilla, 1/2 cup chopped nuts of choice-optional. Beat until smooth with a spoon. Ice cake while hot. Let sit over night.