Grease a fat pan (approx. 32 x 39 cm) and sprinkle with breadcrumbs. Mix cocoa and about 175 ml boiling water to a creamy mixture. Let it cool down
Separate eggs. Beat the egg yolks, 300 g sugar and vanillin sugar in a large bowl until creamy. Stir in the quark, pudding powder and lemon zest. Stir the cocoa mass under 1/3 of the cheese mixture
Beat the egg white in 3 portions until stiff, adding 2 tablespoons of sugar to each portion. fold 2 portions of beaten egg white into the light cheese mixture and 1 portion of beaten egg white into the dark cheese mixture
Spread the light cheese mixture on the fat pan. Dark
Spread the cheese mixture as a blob. Pull through both masses spirally with a fork. Bake in the preheated oven (electric cooker: 175°C / convection oven: 150 °C / gas: level 2) for about 1 hour. Leave to rest in the switched off oven for approx. 10 minutes. Allow to cool down
Whip the cream until stiff. Cut the cake into about 32 triangles. Decorate with cream tuffs. Break the chocolate into pieces, melt in a hot water bath and allow to cool slightly. Use a spoon to spread as strips on the cream tuffs. Allow to set