Hi, I have been thru the 3 Wilton Courses for cake decorating but still consider myself to be a novice. I have done 2 tiered cakes using pillars but have not done a stacked one. When you stack them does the second layer have a separator plate that is placed directly on the first layer? How do you stop the frosting from coming off the bottom layer when the top one is removed? Does it make a difference if you are doing a chocolate ganache icing vs a chocolate buttercream...