Get a cake mix and make how the instructions tell you.
When you made it put it in a round dish and cook for how long it takes.
Make buter cream icing, coulor it and flavor it how you want.
Put it in a bag and pip on the cake.
Use a serated cage nife to smoth it off.
Stack it on top two times.
Do a crumb coat on the cake and freeze it.
Cover again. Enjoy you decorated cake.