Does anyone have a recipe for a non-crusting, stay soft and moist, frosting? The buttercream recipe I use now is half butter, half shortening, powdered sugar and little water. Its good for a few hours but then crusts over. I don't like crust, not on cupcakes. I want a recipe that doesn't need refrigeration and last 2-3 days without crusting. Is there such a thing?

Thanks!

I was going to suggest a SMBC because it can be smooth, silky and soft but I don't know about the no refrigeration part. I'm hoping someone else can answer that.