I love using the upside down icing method with ganache, but I'm wondering if anybody has had success with buttercream. If so, what type of buttercream did you use?
I use the upside down method with pretty much anything that will firm up in the fridge - ganache, BC, and IMBC/SMBC.
The American BC I use has half shortening and half butter - I prefer this too. It crusts nicely and works well with the upside down method as well. You want to be sure to chill the cake though for at least a half hour before flipping it back over and peeling the top off.
jessicacakes: with a note from the original inventor Jeff Arnett: