1 box yellow cake mix
4 tbsp. cocoa
1 stick butter
2/3 c. milk
2 c. sugar
1 tsp. vanilla

Bake cake according to package directions. Cool and split 2 layers into 4 thin layers. Place remaining ingredients in saucepan and bring to a boil on medium heat. Boil for 3 minutes, stirring constantly.

Icing will be very thin but just keep spooning it over layers until covered and icing is used up while still hot.