Beat the butter and powdered sugar until fluffy, then add the eggs one by one.
Mix baking powder, flour, nuts and vanilla sugar and add to the butter mixture.
Finally, add the chocolate chips and mix.
Put the dough on a small baking tray and bake at 175°C top/bottom heat for 35-40 minutes.
Let the dough cool and then cut off the top layer about 1cm thick.
Crumble the “lid” and mix it with 2 tablespoons of cocoa powder.
Now mix the Guma pâtisserie cream with the sugar for 3-4 minutes until creamy, then briefly stir in the chocolate flakes.
Peel the bananas, cut them in half lengthwise and spread them on the dough.
Pour the gumacream on top and smooth it down, finally spread the dough crumbs generously on top of the cream. Enjoy the cake as fresh as possible because of the bananas.