Mix the sugar, vanilla sugar and eggs for a few minutes until frothy. Mix the baking powder, flour, salt and cocoa powder and mix in briefly alternately with the milk on a low level.

Fold in the mashed or mashed bananas and grated zucchini (if the zucchini are very moist, briefly squeeze them in a colander). Fill the dough into a springform pan (base lined with baking paper, greased edge) and bake in the preheated oven at 175 degrees for about 45 - 55 minutes on the middle rack.

Remove the cake from the mold after cooling and dust with powdered sugar or brush with a glaze. The consistency of the cake is very "soggy" and moist, more like a brownie consistency.