Melt 40 g butter in a small pot, add 125 g sugar and jam. Bring to the boil while stirring and simmer for about 3 minutes. When the mixture is caramelised and golden brown, put it immediately into a greased springform pan (approx. 26 cm Ø) and spread it out.
Let it cool down.
Wash the plums, drain well, cut in half and stone. Place the plums on the caramel layer with the cut surface facing down in flakes.
Cream 125 g butter, 125 g sugar, vanillin sugar and salt with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour and baking powder, add together with the milk and stir in briefly.
Spread the dough evenly on the plums.
Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 40-45 minutes (stick test). Cover the cake if necessary approx. 5 minutes before the end of the baking time. Remove the finished cake from the edge with a knife and turn it over onto a cake plate.
Let it cool down. Roast the almonds in a pan without fat, take them out, let them cool down and sprinkle them on the cake. Dust with icing sugar. Whipped cream tastes good with it.