Mexican Chocolate Cake

INGREDIENTS
Cake
2 cups flour
2 cups sugar
1/2 cup butter
1/2 vegetable oil
1 cup water
1/4 cup unsweetened cocoa powder
2 eggs
1/2 cup sour milk
1 teaspoon baking soda
2 teaspoons cinnamon
1 teaspoon vanilla

Pour-Over Frosting
1/2 cup butter
1/4 cup unsweetened cocoa powder
6 Tablespoons milk
1 box (or more) powdered sugar
1 teaspoon of vanilla

INSTRUCTIONS
Cake
Preheat oven to 350ºF. In a large bowl, mix together the flour and sugar and set aside. in a saucepan, heat the butter, oil, cocoa, and water until the butter is melted. Stir it up and pour it over the flour and sugar mixture. Then add everything else (beat the eggs a bit before adding them). Beat the batter until everything is well blended. Bake in a 12x18x2" pan that has been greased and floured for 25 to 30 minutes.

Frosting
In a saucepan, combine the the butter, cocoa, and milk and heat it to boiling and make sure the butter is melted. Remove it from the heat and beat in the powdered sugar. The recipe calls for one box of powdered sugar, but I always use more. Add the vanilla and beat one more time, and them pour it over the warm cake.