Wash, halve and stone the plums. Mix fat, 100 g sugar, vanillin sugar and salt for about 5 minutes until creamy. Stir in 2 eggs one after the other. Mix 200 g flour, almonds and baking powder and finally stir in briefly together with the lemon juice.
Spread the dough into a greased springform pan (26 cm Ø) dusted with flour. Put plums on top. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 45 minutes.
In the meantime, grate the marzipan roughly. Add 1 egg and whisk smooth with the whisk of the hand mixer. Mix 25 g flour, 50 g sugar and cinnamon, add bit by bit and stir well to make a smooth mixture.
Fill the macaroon mass in a piping bag with a large star nozzle. After 30 minutes baking time take out the cake and spray a macaroon grid on top. Bake for another 15 minutes. Take out and let it cool down on a cake rack.
Meanwhile whisk the egg whites. Turn the almonds first in egg white, then in 1 tablespoon of sugar. Leave to dry. Remove the cake from the mould, dust with icing sugar and serve decorated with candied almonds.