Separate eggs. Beat egg whites and 3 tablespoons of cold water until stiff. Add 75 g sugar. Stir in egg yolk. Mix flour, cornstarch and baking powder, sieve onto the egg mixture and fold in carefully. Line the bottom of a springform pan (26 cm Ø) with baking paper.
Fill in the dough and smooth it down. Bake in the preheated oven (electric: 175°C/ gas: level 2) for about 20 minutes. In the meantime, peel three apples, quarter them, core them and cut them into pieces. Bring lemon juice, 25 g sugar and a little water to the boil and cook the apple pieces for about 3 minutes. Drain the apple pieces on a sieve and collect the lemon water. Remove the cake base from the oven, remove from the springform pan, let it cool down and cut through horizontally once. Mix quark, vanilla sugar, calvados, remaining sugar and crème fraiche. Whip 250 g whipped cream for 1/2 minute, add san-apart, beat until stiff and fold into the quark mixture. Fold apple pieces into the quark cream mixture, spread evenly on the cake base and place the second base on top. Whip the rest of the cream until stiff. Spread the cake with 2/3 of the cream. Pour the rest of the cream into a piping bag with a star-shaped spout and squirt tuffs onto the cake.
Mix quark, vanilla sugar, calvados, remaining sugar and crème fraiche. Whip 250 g whipped cream for 1/2 minute, add san-apart, beat until stiff and fold into the quark mixture. Fold apple pieces into the quark cream mixture, spread evenly on the cake base and place the second base on top. Whip the rest of the cream until stiff. Spread the cake with 2/3 of the cream. Pour the rest of the cream into a piping bag with a star-shaped spout and squirt tuffs onto the cake. Put the cake in a cool place for about 1 hour. Wash the rest of the apple, quarter it, core it, cut it into slices and steam it in lemon water for about 2 minutes. Drain well on a sieve and dab with kitchen paper. Just before serving the cake, add 40 g of chocolate to the edge of the cake. Decorate the cake with the apple slices and remaining chocolate. Makes 16 pieces
Put the cake in a cool place for about 1 hour. Wash the rest of the apple, quarter it, core it, cut it into slices and steam it in lemon water for about 2 minutes. Drain well on a sieve and dab with kitchen paper. Just before serving the cake, add 40 g of chocolate to the edge of the cake. Decorate the cake with the apple slices and remaining chocolate. Makes 16 pieces