Beat the fat, salt and 125 g sugar until creamy. Separate the eggs and stir in the egg yolks one after the other. Mix flour and baking powder and stir in briefly together with the milk. Grease a springform pan (26 cm Ø) and spread half of the dough. Beat the egg white until stiff, gradually fold in 200 g sugar. Beat the beaten egg whites until they are smooth and shiny. Pour the meringue mixture into a piping bag with a medium-sized star-shaped spout. Spray half of the meringue mixture in tuffs onto the filled sponge mixture. Leave 1-2 cm of rim free all around
Bake in the preheated oven, 2nd rail from below (electric oven: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 25 minutes. Chill the rest of the meringue. Remove the finished base from the mould. Wash the mould and bake a second base from the remaining dough and meringue. Let it cool down
For the compote, wash, halve and stone the plums. Cut plum halves into slices. Boil up cherry nectar and 3 tablespoons sugar. Add plums and simmer for about 1 minute. Stir starch and some water until smooth. Stir into the boiling liquid and simmer for about 1 minute while stirring. Let the compote cool down while stirring occasionally
For the cream, soak gelatine in cold water. Mix sour cream, 60 g sugar and vanillin sugar. Squeeze the gelatine and dissolve it carefully in a small pot. Stir 3 tablespoons of sour cream mixture into the gelatine, then stir everything into the rest of the mixture. Chill the cream until it starts to gel. In the meantime, whip the cream until stiff and fold into the gelling cream
Carefully stir the compote again and spread on a meringue base. Pour the sour cream over it and spread it loosely. If the cream is still very soft, chill the cake for about 30 minutes. Then place a second base on top. Chill the cake for about 3 hours. Dust with icing sugar
waiting time approx. 3 1/2 hours