Brownie Sheet Cake
["1/2 c. oil", "1 stick butter", "1 c. water", "4 Tbsp. cocoa", "2 c. self-rising flour", "2 c. sugar", "1 tsp. soda", "1/2 c. buttermilk", "2 well beaten eggs", "1 tsp. vanilla", "1 stick butter", "4 Tbsp. cocoa", "6 Tbsp. milk", "1 box powdered sugar", "1 tsp. vanilla", "1 c. chopped nuts (optional)"]
["Bring to a boil the oil, 1 stick butter, water and 4 tablespoons cocoa.", "Have ready flour, sugar and soda.", "Pour the boiled mixture over the dry mixture; mix quickly.", "Add buttermilk, eggs and 1 teaspoon vanilla.", "Pour in a sheet cake pan, 11 x 16 inches.", "Bake for 20 minutes at 400\u00b0."]
["oil", "butter", "water", "cocoa", "flour", "sugar", "soda", "buttermilk", "eggs", "vanilla", "butter", "cocoa", "milk", "powdered sugar", "vanilla", "nuts"]