Separate the eggs. Mix the egg yolks with 50 g sugar, vanilla sugar and 3 tablespoons cold water until foamy. Beat the egg white with a little salt and 50 g sugar until stiff and fold into the egg yolk mixture. Mix the flour and baking powder, sift over and fold in. Fill into a springform pan and bake at 150 ° C for about 25 minutes. Let cool in the springform pan.
Grate the apples and mix with 125 g sugar, then mix the pudding powder in a saucepan with 125 ml water. Add the butter and the grated apples and bring to the boil, stirring constantly. Simmer for a few minutes, allow to cool a little and place on the sponge cake base.
Let cool for at least 2 hours and only then remove the springform pan.
Whip the cream until stiff, add a packet of cream stabilizer if necessary, and distribute it on the cake in a grid shape. Garnish with chocolate shavings and serve.