Knead flour, 125 g sugar, vanillin sugar, salt, crème fraîche, 1 egg and cold fat in flakes to a smooth dough. Cover and chill for about 1 hour. In the meantime, finely chop the candied lemon peel and candied orange peel.
Crush marzipan. Mix both with nuts, the second egg, remaining sugar, lemon peel and lemon juice. Cut open the freezer bags. Roll out the dough in between to a rectangle of about 30x50 cm.
Peel off the top bag and brush the dough with egg white. Add nut mixture and smooth it down. Roll up the dough from both long sides towards the middle. Spread the "seam" with egg white and press the dough slightly together.
Leave to cool for about 2 hours in the refrigerator. Cut the dough strand into approx. 7 mm thick slices. Place on baking trays lined with baking paper and bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 12-15 minutes one after the other.
Let it cool down. Melt the couverture and dip half of the cookies 1/3 into the couverture. Let dry on a cake rack. Makes about 60 pieces.