I have had three major mixing mousse and fondant disasters. I need to prevent a 4th but the cake is due Saturday. I am making a plain yellow cake filled with French vanilla mousse. Here is where I get confused, scared and very frustrated: 

Can I use the mousse to fill and ice then cover with Fondant? I have to mention that this has failed miserably in the past..(cake sliding etc.) Although I will take any suggestions if it worked for you, perhaps a more stabilized mousse recipe and denser cake combo? 

But I am thinking I should fill with the mousse, THEN dam and ice with buttercream then cover with fondant? Is that right? 

Any help would be much appreciated. 

No, no, no on the icing with mousse.   You will have a 4th disaster.

To fill make a butter cream damn first...THEN fill with mousse.   Make sure your filling isn't higher than your damn.

Ice with either ganache or butter cream. 

Yay! Thanks so much! I looked around and found a recipe by indydebi that people are raving about. I will give it a try and hopefully I will have great pics to post!

Thanks again, especially for the quick reply.