Cream the butter, cream cheese and vanilla in the bowl of a stand mixer. Add powdered sugar 1/2 cup at a time. Blend on high until the frosting is light and fluffy.

Frost cake after it has completely cooled. 

This is enough frosting to frost the entire cake or if you only want to frost the tops of each cake, this frosting will be enough for two cakes or a batch of cupcakes.