I am fairly new to cake making. I have an order placed for a chocolate cake with peanut butter mousse. Client has left it to me to decide what frosting to use. Any and all suggestions would be appreciated. I typically use buttercream. Is that okay for a chocolate cake? Should I use ganache? Chocolate buttercream? Helppppp!! LOL! Thanks SO much!!! 

APersonally, I would use either chocolate buttercream or peanut butter frosting with chocolate ganache drizzled over the top.

AIs this a decorated cake or a dessert cake? If it is to be decorated, I would use buttercream, and if it is dessert, I would use ganache.

I guess I should have said the cake will be fondant covered... Does that make a difference with the ganache?

ANope, you can cover it with ganache and then fondant! Yum!