I have a client requesting a stacked cake (8" and 6" layers) and then topped with the Tinkerbell tree in fondant covered rice krispies. She requested the layers be filled with chocolate mousse and fresh strawberries. I'm concerned about the stability of the cake if it's filled with mousse and fresh fruit. I know I can seal in the strawberries with buttercream, but I've never done this with mousse. My concern is that as the cake sits out at the party, it's going to sink as the mousse warms and the tree will topple over. Also, not sure if moisture from the berries will do anything to the consistency of the mousse...
If you mean a real mousse then yes, the cake would need to be refrigerated. The strawberries will "leak" into the mousse and the liquid will break down the mousse.
I would tell the client that as long as the cake stays refrigerated then it will be ok, if she doesn't want to keep it cold I would advise her to choose something more stable.
I would suggest that instead of doing the mousse and the strawberries in the same layer of filling, you torte the cake to do alternating layers of filling. So....
Or, do the strawberry filling in one tier and mousse in the other.
Either way the cake will need to be refrigerated.
As long as the internal structure (dowels) is done correctly, neither the mousse nor the strawberries should affect the stability of the cake.
Cake should be fine out at the party for an hour or so, as long as the room isn't super hot (over 70 degrees).
Thanks! I like the idea of alternating layers. I'll run this by her.