For the short pastry, mix flour, 60 g sugar and 1 pinch of salt in a bowl. Add 1 egg and 125 g butter in flakes. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap in foil and chill for about 30 minutes. Grease a springform pan (26 cm Ø, high rim). Roll out the dough on a floured work surface until round (approx. 31 cm Ø). Line the form with the dough, press the rim well
Melt 50 g butter, let it cool down a little. Separate 5 eggs. Whisk egg yolks and 200 g sugar with the whisk of the hand mixer until thick and creamy. Gradually stir in mascarpone and quark. Stir in lemon zest, lemon juice and butter. Sift the starch on top and fold in. Beat egg white until stiff. Add 1 pinch of salt and 100 g sugar, fold in carefully. Put the mixture into the form
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for approx. 35 minutes. Remove from the oven and cut diagonally into the cheese mixture to a depth of approx. 2 cm around the edge of the mould. Let rest for about 10 minutes, then bake for another 20-25 minutes. Let it cool down on a cake rack. Remove the cake from the tin and place on a plate
Wash the blackberries and drain well. Heat jelly in a pot and bring to the boil briefly. Add blackberries and mix in. Spread on the cheesecake. Dust the rim with icing sugar
Waiting time approx. 5 hours