So I have never made a mousse cake before and was wondering if a cake filled with mousse can be served at room temp or does it have to be cold?

I am planning on making a chocolate cake with chocolate mousse and the frosting will be buttercream.  Will the mousse ooze out of the cake once it returns to room temp?  will making a buttercream dam help? 

TIA!!!

A buttercream dam can help keep it inside the cake, but take into account that regular chocolate mousse shouldn't be outside of the refrigerator for too long, it isn't shelf stable...

Well, you should have about a two hour window after it comes out of the fridge. I'm just going by the many times I've taken the serve safe classes. 

Thank you for your responses. I should have specified that the cake is just for me and my husband (fr our anniversary) and i do not intend to sell it. I understand it from sanitation point of view but i was just concerned about the structure of the cake. If the filling would ooze out or not making it look not so appealing. We prefer to eat our cakes at room temp :)

you can leave it sit out a bit before cutting then just let the sliced servings sit out for a few before eating -- or microwave for 5 seconds -- i microwave my ice cream i like it soft -- but you run the risk of it being too soft to serve best if it cools off all the way -- it squoshes less when it's cold

happy anniversary best wishes to you