Cream fat and sugar. Stir in eggs bit by bit. Mix flour and baking powder and stir into the fat egg mass. Put the dough into a springform pan (26 cm Ø) lined with baking paper and smooth it down. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 15 minutes.
Let it cool down in the tin on a cake rack. Wash the plums, dab dry, cut 3 plums into slices and quarter the remaining plums, removing stones. Whip cream for 1/2 minute. Stir in 4 teaspoons of cream and cream firming agent and beat until stiff. Mix quark, sugar and lemon juice. Mix cream, up to 125 g for decorating and the remaining cream firming agent and mix with the quark. Spread plum quarters on the base, add quark mixture and smooth it down. Put the cake in a cool place for about 2 hours. Remove from the mould. Pour the rest of the cream into a piping bag with a perforated spout and squirt it onto the cake as a dab.
Mix cream, up to 125 g for decorating and the remaining cream firming agent and mix with the quark. Spread plum quarters on the base, add quark mixture and smooth it down. Put the cake in a cool place for about 2 hours. Remove from the mould. Pour the rest of the cream into a piping bag with a perforated spout and squirt it onto the cake as a dab. Decorate with plum wedges and pistachios. Makes 12 pieces