Melt the nougat over a warm water bath. Cream the room-warm fat, sugar, salt and 1 packet of vanilla sugar with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour, baking powder and hazelnuts and stir into the dough alternating with the milk. Mix in the nougat. Put the dough into a greased springform pan (26 cm Ø) sprinkled with breadcrumbs and smooth it down. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for about 30 minutes.
Remove from the oven, loosen the ring and let it cool down on a grid. Take the cake out of the tin and place it on a plate. Stir mascarpone, quark, icing sugar, rest vanillin sugar and rum until smooth. Spread the cream wavy on the base and chill. Drain the pineapple. Put pineapple on the cake before serving. Decorate with lemon balm as desired