For the applesauce slices, beat eggs with 250 g sugar and vanilla sugar until foamy. Mix in water and oil.
Mix flour with baking powder, sift onto the mixture and fold in. Spread the mixture on a small baking tray (or in a pull-out frame).
Bake in preheated oven at 175 °C for about 25-30 minutes and let cool. Whip the cream with cream stiffener until stiff.
Mix the sour cream with 1 tablespoon sugar and fold into the whipped cream. Spread applesauce on the cooled cake and top with a layer of sponge cake.
Then spread the whipped cream on top. Sprinkle with cinnamon and refrigerate the applesauce slices.