Any suggestions for doing this? I's like to use a rather thick layer between cake layers but I'm afraid that even with correct dowel rodding, the icing wont keep the mousse in. The cakes I'm referring to are the Rolfs Patisserie cakes that they sell at Whole Foods in the Chicago area. I tried to make a couple last week on a day that was really hot and humid. I made a peanut butter mousse and a chocolate mousse, Two different cakes. I covered them both well and put them in an pre-airconditioned car and by the time I got where I was going, one cake had collapsed the other I circled with a clear cake collar. That one was fine. I'd like to beable to cover them with butter cream or fondant and stack.
I know this is rambleing but I have a lot going on right know.

I'm not sure what you're asking, but as long as you have a stiff dam of buttercream, the filling should stay put, no matter what it is. I used peanut butter mousse in a wedding cake last weekend with no problems.

i've used mousse in tierede cakes with no problem and a shop I used to work in only used mousse in all their cakes. Is your mousse stable enough. Once mousse sets it should be firm enough to stnd up to be a filling. What recipe are you using?

I use pastry pride whipped topping. Its more stable than whipping cream. I also add instant pudding to it, or for chocolate I add melted chocolate. The pudding makes it thicker and doesn't move around when I stack my wedding cakes. You don't have to refrigerate, I always do though.

Thank you all for your advice ! I'm going to look at the stableization issue and am also going to look into using cake rings to set the cakes up.
Thanks again !