Surely I can have the best of both worlds! I adore the sharp edges I finally get with ganache! But when I try to cover the cake with fondant (mmf to be specific), it tears right along the crisp edge! Argh! Surely, I could rub the edge to round it but that defeats the purpose! What am I doing wrong? I tried adhering quickly before the weight had a chance to pull at all but the back tears while I'm adhering the front & sides!

Thanks for your help!

I feel your pain. I find it worse when I either roll the fondant super thin, or when the weather is very dry. Adhering the top edges very quickly is all the advice I can offer, sorry. I know that's not very helpful.

Perhaps this video from inspiredbymichelle might help:

http://www.youtube.com/watch?v=imfDvvSZn5I&feature=youtube_gdata_player

I know she doesn't address fondant tears, but perhaps her method of smoothing & shaping the edges can provide some help.