I'm going to be doing a Transformer cake and would like to try out the Melvira method. Only prob is that I would like to do an alternative frosting to buttercream. It's for a bunch of young children and would like to keep the unhealthy ingredients (shortening) to a minimum! I really enjoy marshmallow BC but don't know if this would work as I don't think it crusts! Any input into this topic would be greatly appreciated, the cake is for the 28th of Feb. Thanks so much! 

In order for the Melvira method to work, the icing has to crust. I can't see it working on anything but a crusting buttercream.

Do you or anyone else have a recipe for a really great tasting crusting frosting?