Separate eggs. Beat the egg whites with the whisks of the hand mixer until stiff, adding 100 g sugar, 1 packet of vanillin sugar and salt. Add egg yolks and stir in. Mix flour, buckwheat flour and baking powder. Sieve portions onto the egg-sugar mixture and fold in
Line the bottom of a springform pan (26 cm Ø) with baking paper. Add the sponge mixture, smooth it down and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 25-30 minutes. Remove the cake from the oven, place on a cake rack, remove from the edge of the springform pan and allow to cool in the pan
Soak gelatine in cold water. Remove the base from the springform pan, cut in half horizontally and spread the lower base with 6 tbsp. fruit spread. Place a cake ring around the base
Mix quark, 100 g sugar and 1 packet of vanillin sugar. Whip the cream until stiff. Squeeze the gelatine, dissolve and mix with 4 tbsp. quark, then stir into the remaining quark. Fold in the cream. Spread the cream, up to 6 tbsp, on the base until smooth. Place the cake lid on the cream and press down gently. Spread the rest of the cream loosely with a tablespoon on the lid and refrigerate for approx. 4 hours
Sort and wash the blueberries. Wash the currants and remove from the panicles. Mix 4 tablespoons of fruit spread with the berries. Remove cake ring. Cut the cake into 12 pieces and spread the berries on top
waiting time approx. 5 1/2 hours