Cream soft fat and 100 g sugar. Stir in eggs one after the other. Mix nuts, flour and baking powder, alternating with the milk. Put the dough into a greased springform pan (26 cm Ø) and smooth it down. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 25-30 minutes. Let it cool down.
Soak gelatine in cold water. Mix quark, 100 g sugar and vanillin sugar. Dissolve gelatine, mix with 3 tablespoons of the quark cream, then stir everything into the remaining quark. Whip cream until stiff and fold in. Pour cream on the base and smooth it down. Put in a cool place for at least 2 hours. Peel grapefruits so that the white skin is completely removed. Cut out the fillets of the light grapefruit between the parting skins, cut pink grapefruits into slices. Spread the fillets and slices over the cake. Mix the cake glaze with 30 g sugar in a small pot, gradually adding 250 ml water. Bring to the boil while stirring.
Put in a cool place for at least 2 hours. Peel grapefruits so that the white skin is completely removed. Cut out the fillets of the light grapefruit between the parting skins, cut pink grapefruits into slices. Spread the fillets and slices over the cake. Mix the cake glaze with 30 g sugar in a small pot, gradually adding 250 ml water. Bring to the boil while stirring. Let the icing cool down a bit, spread it on the cake with a spoon. Cool again and let it set. Cut the cake from the mould. Warm up the jam, spread a thin layer on the edge and sprinkle the nuts on the edge, press down slightly. Decorate with lemon balm as desired
Let the icing cool down a bit, spread it on the cake with a spoon. Cool again and let it set. Cut the cake from the mould. Warm up the jam, spread a thin layer on the edge and sprinkle the nuts on the edge, press down slightly. Decorate with lemon balm as desired
waiting time approx. 3 1/4 hours