Brownie with chocolate mousse on top I want to make a cake that involves a brownie layer with chocolate mousse on top. I just want to use my own trusted brownie and chocolate mousse recipes. I've looked it up and found a few similar recipes.

Now, I'm worried that the chocolate mousse might have a bit of fluids at the bottom that will ruin the brownie layer. Is there anything I can do to improve this (I was thinking of a small layer of chocolate that will prevent absorption of the fluids by the brownie) and is it generally a good idea to combine the two or am I better off making a regular chocolate cake layer instead of a brownie?

Thank you for your advice
Brownies are thicker than a standard cake sponge, but either can absorb moisture, if you want to prevent that then a thin layer of chocolate frosting would work fine, or as you suggest a thin layer of chocolate. 

It is opinion based whether I think a brownie or a sponge would be better with mousse, what I will say is that the consideration is the difference in consistency between the two. A rich, soft mousse on top of soft, fluffy cake may more people than hitting a thick, harder layer of brownie, but it all depends on the effect you are looking for.