Grease a springform pan (26 cm Ø). Melt 150 g butter and let it cool down a bit. Mix flour, 150 g sugar, vanilla sugar and 1 pinch of salt in a bowl. Add the butter and knead everything into crumbles with a hand mixer.
Approx. 2⁄3 Press the crumble into the springform pan as a base. Pre-bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 10 minutes. Then take out.
Select the currants, wash them and remove them from the panicles. Stir starch and 5 tablespoons of nectar until smooth. Boil up the rest of the nectar and 3 tbsp. sugar. Stir in the starch. Bring to the boil while stirring and simmer for about 1 minute.
Stir in approx. 3⁄4 of the currants, let it cool down for approx. 10 minutes. Pour onto the base and smooth down. Let it cool down.
For the quark mixture, stir 125 g butter and 125 g sugar until creamy. Stir in lemon juice and eggs one after the other. Also stir in the quark and pudding powder. Carefully spread the quark mixture on the compote.
Mix the remaining berries and crumbles and sprinkle on the curd mixture. Continue to bake the cake at the same temperature for approx. 50 minutes (if necessary cover the last approx. 10 minutes). Let the cake cool down for about 4 hours.
Dust with icing sugar and decorate with currants. Whipped cream tastes good with it.