Beat eggs and sugar until frothy. Fold in the flour and cocoa.
Bake in a round springform pan at 180 ° C for approx. 10-15 minutes. Let cool and take out.
Whip the whipped cream until stiff.
Mix the quark, sugar, lemon juice and vanilla sugar together.
Soak gelatine in a water bath and dissolve in a saucepan.
Add 1 - 2 tablespoons of the quark mixture to the gelatin in the pot and dissolve it. Then add the gelatin mixture to the rest of the quark mixture and stir well.
Put in the whipped cream.
Mix 300g of the quark mixture with the cocoa.
Lay out a sheet of cling film on the bottom of the springform pan. Brush the form with oil.
Then spread the dark curd mass on the foil like a cow stain. Leave the gaps open. Then fill the remaining quark mass in between and smooth the top.
Put the cake base on top and press down a little.
Cover with foil and let cool in the refrigerator for about 4 hours.