I need to cover my two tier cake and my fondant bubbly and a bit moist. How can I fix my MMF????? Should I roll it out w/ cornstarch or powdered sugar????

bubbly?

Powdered sugar. And is it warm? Let it cool a bit.

Perhaps you should knead a bit more PS into it to firm it up. Did you let it sit overnight? For rolling it out before covering a cake, I greatly prefer cornstarch--doesn't require nearly as much to roll out, works great to prevent sticking, and won't dry out the fondant like PS ('cuz you use less). But if your fondant is loose, you may just have to get more PS into it before rolling it out to cover your cakes. HTH!

When did you make your fondant. It should sit for a minimum of 8 hours before you work with it.

I use powdered sugar to roll mine out...unless my fondant gets too "dry" while making it, then I use cornstarch. Typically I try to roll it out when it is slightly less firm than I want so that when I roll it with PS it doesn't get too dry and is perfect consistency when I put it on the cake.

Also - I have let my fondant sit 1/2 hour to 1 hour before using it and had no problems. In fact, the only time I let it sit more than that is if I am making a cake that requires I have to make more than one batch of fondant..I will make a batch one night, then another the next night which is typically when I decorate the cake - so the first batch sits until the second night. I work full-time and do this on the side so my cakes are made in the evenings or on weekends - if you do this during the day, you can make everything the same day and just let the fondant sit for minimum 1/2 hour.

sounds like you have too much liquid in your fondant and that you just made it. if it's the mmf recipe from this site, i recommend you let it sit for a while...or use a lot of powdered sugar.