Yellow filling: beat egg yolks and 250g of sugar until foamy. Steam them until the mass thickens. When completely cooled, add margarine and vanilla sugar. Mix well and combine the mass.

Brown filling: beat stiff egg whites while adding sugar little by little (250g). Finally, add ground biscuits and walnuts. Mix well and combine the mass.

Put half of the yellow filling on the first sheet of wafer, put half of the brown filling on the second sheet, put the remaining yellow filling on the third sheet, put the remaining brown filling on the fourth sheet, finish with the wafer sheet. Cover the top sheet of wafer with a napkin, press down with a heavy tray, leave the cake to cool and harden. If desired, you can cover the cake with chocolate glaze.