First cream the butter until fluffy, then stir in the sugar and eggs.
Also stir in the flour, baking powder, nuts and spices. Spread 2/3 of the dough on a baking tray lined with baking paper and bake at 160 °C for 20 minutes.
Remove from the oven and spread the jam on top, make a lattice with the remaining dough and bake again for 15 minutes.
Cut the cooled Linzer slice into cubes.