Beat the butter until frothy. Stir in 125 g sugar, also the egg yolks. Then stir in the flour mixed with the baking powder. Spread the dough in a springform pan. Spread the jam on top (possibly mixed with a little liqueur).
Beat the egg whites until stiff, stir in the remaining sugar and fold in the ground nuts or almonds. Spread the mixture on the jam. Bake at 175 ° C for about 45 minutes (correspondingly less hot air).
Annotation:
An old family recipe from my mother`s family, it was a must for every birthday or wedding. It can be kept in a cool place for a long time and can therefore be baked beforehand. For a large baking sheet, simply use double the amount.