Clean, wash, halve and stone the plums. Separate eggs. Beat the fat and sugar, 1 pinch of salt and lemon zest with the whisk of the hand mixer until foamy. Stir the egg yolks into the fat mass one after the other. First stir in flour, then 5 tablespoons of milk. Beat the egg white until stiff and fold into the dough in portions
Fill the dough into a greased and breadcrumbed springform pan (26 cm Ø) and smooth it down. Place the plums on the dough with the curvature upwards
Heat the jelly. Spread the plums with it. Bake the cake in a hot oven (electric cooker: 175 °C/ convection oven: 150 °C / gas: level 2) for about 1 hour. Remove from the tin, let cool down
Put 1/4 l milk in a bowl. Add sauce powder while stirring. Beat vigorously for about 1 minute. Dust the cake with icing sugar. Add vanilla sauce