Bake the chocolate cake in 3 9″ pans. Level the cooled cake layers.
Prepare the chocolate mousse filling. Peel and cut the bananas into slices.
Assemble the cake starting with the first cake layer. Spread some of the chocolate mousse over it, place banana slices on top and finish with some more mousse.
Place the second cake layer on and repeat. Finish with the last cake layer. Ice the top and the sides with the mousse and place the cake in the fridge.
Prepare the chocolate glaze and let it cool down until it barely feels warm but is still spreadable. Spread the glaze over the mousse iced cake. If you have remaining mousse you can pipe little rosettes on as decoration or use some sugar pearls as in this picture.