Line the bottom of a springform pan (approx. 18 cm Ø) with baking paper. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Separate the eggs. Beat the egg white, 50 g sugar, vanilla sugar, 2 tbsp cold water and 1 pinch of salt until stiff with the whisks of the mixer.
Stir in the egg yolk. Mix flour, starch and baking powder, sieve on top and fold in.
Smooth out approx. 1⁄4 of the sponge cake mixture in the mould and sprinkle with 25 g almonds. Bake in a hot oven for about 12 minutes. Take it out of the springform pan. Bake 3 more cakes with the rest of the sponge mixture and almonds.
If necessary, clean the springform pan in between. Let all floors cool down.
Wash, halve and stone the plums. Wash the lemon hot, dry and finely grate the rind. Stir pudding powder and 5 tbsp. cherry nectar until smooth. Rest nectar, lemon peel, 3 tablespoons sugar and 1 Msp.
Boil up the cinnamon. Add plums and simmer for 2-3 minutes, stirring continuously. Stir in the pudding powder and continue to simmer for about 1 minute. Let it cool down for about 10 minutes, stirring more often.
Spread the plum compote evenly over 3 soils. Let it cool down. Beat the sour cream and icing sugar with the whisks of the mixer until stiff. Spread the cream over all 4 cake layers. Place the soils with compote on top of each other, place the soils without compote on top.
Chill for about 1 hour. Possibly decorate with edible flowers.