Cream butter in a standing mixer for about 5 minutes or until fluffy.
Keeping the mixer on, add the vanilla.
Add the powdered sugar, a little at a time until fully incorporated. With about half of the sugar in, add 2 tbls. of whipping cream.
Pour in the rest of the powdered sugar and then the remaining 2 tbls. of whipping cream. Continue mixing until you get a nice, fluffy, creamy consistency.
Add any other flavorings or color and store in the refrigerator until it's ready to be spread. Can be made ahead of time. Double recipe for two 9 inch cakes.