Chopping chocolate. Melt with the butter over a warm water bath. Coarsely chop the nuts and almonds. Whisk the eggs with a whisk. Mix flour, sugar, vanillin sugar and salt in a bowl.
Add eggs and chocolate mixture. Mix everything briefly with the whisk of the hand mixer to a smooth dough. Grease a springform pan (26 cm Ø) and dust with flour. Fill in the dough and smooth it down.
Add the nut mixture and press down a little. Sprinkle with brown sugar. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 25-30 minutes. After about 15 minutes of baking time, spread the jam in blobs on the nuts.
Finish baking. Use a knife to remove the cake from the edge of the tin. Leave to cool in the mould on a cake rack.