Mix flour, baking powder and 150 g sugar. Cut 300 g butter into small cubes. Add quark, eggs and butter to the flour mixture and knead to a smooth dough. Wrap the dough in foil and chill for about 30 minutes
For the topping, melt 300 g butter. Stir in 300 g sugar, vanillin sugar, 6 tbsp water and almonds. Roll out the short pastry in a greased baking tray (36 x 41 cm). Heat jam and spread evenly on the pastry. Spoon the almond mixture onto the pastry and smooth it down
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 25 minutes. Take the cake out of the oven, let it cool down for a short time and cut it into approx. 42 squares while still warm and cut them diagonally in half. Let the cake cool down
Chop the chocolate and melt over a warm water bath. Coat the opposite corners of the pastry with chocolate and allow to set
waiting time approx. 1 1/2 hours