Mix the sugar, vanilla sugar and yolks until frothy. Add flour and baking powder, gradually pour in oil and water. Finally fold in the stiffly beaten egg white.
Place the dough on a baking sheet and bake at 180 ° C for about 20-25 minutes.
Preparation of the topping:
Mix the yogurt and applesauce, stir in icing sugar to taste.
Fold in the two whipped cream. Spread half of the cream on the cooled base, cover with ladyfingers (do not soak the ladyfingers!) And cover with the rest of the cream.