Grease a 9 by 13 pan and preheat oven 350 degrees.
In a saucepan bring butter coke and oil to a boil. Remove from heat and pour in a large bowl. Beat in the remaining ingredients for the cake. Pour in the pan and bake about 30 minutes. Let cool completely.
For the frosting add the butter and cocoa to a bowl. Beat in the coke chocolate syrup and vanilla. Slowly beat in the powdered sugar until the it reaches the desired consistency
Spread on cooled cake and drizzle the caramel topping over top and serve