For the short pastry, put 125 g flour in a bowl. Add egg yolk, 40 g sugar and butter in flakes. Knead first with the dough hooks of the hand mixer, then quickly with your hands to a smooth short pastry. Wrap dough in foil and chill for about 30 minutes
Roll out the dough on slightly floured baking paper to a round plate (approx. 24 cm Ø). Grease the bottom of a springform pan (26 cm Ø) and dust with flour. Turn out the dough plate. Put a springform ring around the base. Press the base to the edge of the tin and prick it several times with a fork. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) on 2nd rack from the bottom for 15-20 minutes. Take out and let cool down
Separate the eggs for the sponge cake. Beat the egg whites and 2 tablespoons of cold water with the whisk of the hand mixer until stiff, adding 40 g sugar and 1 packet of vanilla sugar. Stir in the egg yolks one after the other. Mix 50 g flour, starch and baking powder, sieve onto the egg mixture and fold in carefully. Grease the bottom of a springform pan (26 cm Ø). Fill in sponge cake mixture and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 20 minutes. Take out and let cool down
Stir 100 g jam until smooth. Spread the short pastry base with jam. Remove the sponge cake from the tin and place it on the shortcrust pastry. Place a cake ring around the base
Soak gelatine in water. Drain the apricots well in a sieve. Finely mash half of the apricots. Mix with quark, sour cream, 80 g sugar and 1 packet of vanillin sugar. Squeeze the gelatine and melt in a small pot. Stir in 3 tbsp. apricot cream, then stir into the rest of the cream. Chill the cream until it starts to gel. Cut half of the remaining apricots into strips. Whip 200 g cream until stiff and carefully fold in with the apricot strips. Fill the cream into the springform pan, smooth it down and chill for at least 4 hours
Chop the chocolate and melt over a warm water bath. Spread a thin layer of chocolate on a marble board or baking tray and let it set. Use a spatula to scrape off a few rolls. Scrape the shavings off the remaining chocolate
Remove the cake from the cake ring. Whip 300 g cream and 1 packet of vanilla sugar until stiff and spread the cream all around. Sprinkle the cake all around with chocolate rolls, except for a few topping or shavings, and refrigerate. Wash and clean the strawberries. Halve the berries and remaining apricots. Heat the rest of the jam with 2-3 tbsp. water and pass through a sieve. Mix with the fruit. Arrange the fruit on the cake. Decorate with chocolate rolls
waiting time approx. 4 hours