Roughly chop the chocolate coating. Mix the fat, 100 g sugar, 1 packet of vanilla sugar and 1 pinch of salt with the whisk of the hand mixer for 2-3 minutes until creamy. Stir in 2 eggs one after the other. Mix flour, cocoa, 25 g couverture and baking powder
Alternately stir in flour mixture and milk. Pour the dough into a greased, flour-spread box form (approx. 25 cm long; approx. 1.5 litres capacity) and smooth it down. mix jam, spread on the dough
Separate two eggs. Mix quark, 50 g sugar, 1 packet vanilla sugar and egg yolks with a whisk. Stir in sauce powder. Beat the egg whites and 1 pinch of salt until stiff, while pouring in 50 g of sugar. fold the beaten egg white into the quark
Carefully fill the cheese mixture into the box mould and spread it. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 1 1/4 hours (cover after approx. 40 minutes). Take the cake out of the oven, let it cool down in the mould on a cake rack for approx. 30 minutes
Turn out the cake, let it cool down for about 2 hours. Melt 25 g chocolate coating over a warm water bath, let it cool down for about 10 minutes. Pour into a freezer bag, cut off a small corner, spray thin lines onto the cake, let it set for about 30 minutes
waiting time approx. 3 1/4 hours