I am in the middle of making 21 cakes and baked cakes already. I started to frost with mocha frosting and my cakes where comming up onto my knife. It was tearing up the cake...What can I do...HELP.............ASAP please.......
Have you tried to do a butter cream "dirty ice" (I think that is the terminology) first? It is a thin layer of bc on the cake(s) then let it sit to crust. After that, you can frost or fondant with great results.
It sounds like your icing is too firm. Try adding a bit of cream or milk and mixing it very well and do the crumb coat before you add your final icing. Should work. You could also chill your cake a bit that helps sometimes too.
Did you let your cakes settle over night first? That helps too.