Grate the marzipan in a mixing bowl. Add the butter in pieces, icing sugar, 1 packet of vanillin sugar and lemon zest and mix with the whisk of the hand mixer. Sift the flour over the mixture and knead. Form a roll (3-4 cm) and wrap in foil. Chill for at least 1 hour (preferably overnight). Whisk the egg yolks. Brush the roll with it.
Mix sugar and 1 packet of vanilla sugar. Roll the dough roll in it. Cut into slices of about 1/2 cm width. Place on a baking tray lined with baking paper. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 12-15 minutes. Let the cookies cool down on a kitchen grid
Waiting time approx. 1 hour