Newbie! I made mmf for the first time (Rhonda's recipe) this week and loved the way it modeled. I was planning on covering my daughter's cake with MMF also, but I am concerned because the models I created seemed to really harden. Will the cake have a "hard shell"? I'm hoping I used too much cornstarch or rolled it too thin. Help! I don't want to have to saw through the cake.

The fondant will harden some, but the buttercream layer under the fondant will keep it from hardening like the figurines.

fondant that is touching a fat source (buttercream, ganache, etc) will stay soft. Allowed to airdry, it will harden. That is why you use Royal icing on fondant (no fat) instead of buttercream to glue things and write.

hope that helps!

Thanks! that makes me feel better about using mmf