My cream cheese buttercream is to thin, how can I thicken it to hold up under fondant?

I like this cream cheese recipe for covering and pipping, I think it would work well under fondant. Especially if you chill the cake till the icing is firm!

http://cakecentral.com/recipe/decorator-cream-cheese[/url]

If you want a true cream cheese buttercream without Crisco, it will not be stiff. You need to chill, work fast to cover while it is hard, and put it back in the refrigerator. Assemble just before serving if you can't chill the whole cake.

My brides/clients choose to do this instead of resorting to Crisco.