First, beat the butter and sugar until frothy. Gradually, the 4 eggs with stirring. Then the flour, nuts, vanilla sugar and baking powder with stir.
Mash the very ripe bananas to a pulp with a fork (a few pieces may still be recognizable). Finally, fold in the banana pulp and the chocolate flakes. Grease a loaf pan and sprinkle with breadcrumbs, pour in the dough.
Bake the cake at 180 ° C top / bottom heat for approx. 50 - 60 minutes.
Those who wish can cover the cake with icing sugar then either or a glaze.