The recipes i made an 8 inch cake, but you are free to use a different baking pan size if you would like. I am using two 8 inch pans one for the chocolate cake and mousse layers and second one for white chocolate mousse so i wouldn’t have to wait for my hazelnut mousse to set before pouring in my white chocolate mousse and than when they both set i just flip the white chocolate layer on top of the hazelnut layer which does require some care and patience. You can always just make it in one pan just make sure to wait for the chocolate mousse to set before making the white chocolate mouse to and pour.
To make it easier for some people i included the recipe for a 10 inch spring form pan. This way you don’t have to worry about dropping the top layer when transferring it to the top.