Can you use a basic chocolate mousse as frosting for a cake? Would it be stable enough or is my layered cake going to fall apart?
My favorite chocolate mousse recipe uses gelatin as a stabilizer. I've used it as a filling between cake layers and it works really well. I don't see why you couldn't use it on the outside of the cake as well.
You'll want to keep the cake refrigerated. I don't know exactly how long it will remain stable, but I've kept it in the fridge for several days without a problem.