Put the lady fingers in a freezer bag, seal it and crumble it with a rolling pin. Melt butter in a pot. Mix butter, espresso, 1 teaspoon cocoa and crumbs well. Grease a tart tin (24 cm Ø), add the crumbs and line the bottom and the edge well with them. Put it in a cold place. Put plums in a sieve and drain well, then place on kitchen paper
Mix quark, sugar, vanillin sugar and lemon juice. Stir in eggs and egg yolk one after the other, then add starch
Cover the crumbly base with plums, add the quark mixture and smooth it down. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 35 minutes. Leave the finished cake to rest in the switched-off oven for approx. 10 minutes. Remove the cake and let it cool down on a cake rack. Cover the tart with a cake topping and dust with approx. 3 tsp. cocoa powder. Remove the tip carefully
waiting time approx. 2 1/2 hours