For the lattice cake, crumble butter and flour well. Mix in nuts, yolks and sugar and knead firmly. Leave to rest in the refrigerator for one hour.
Roll out 2/3 of the dough and place on a baking sheet. Form the rest into thin rolls. Spread jam on the dough on the baking sheet and make a grid on the jam with the dough rolls.
Bake at 180 °C (top and bottom heat) for about 45-50 minutes. Cut the cooled lattice cake into small pieces.