Mix the hazelnuts, almonds, sugar and cinnamon in a bowl
Chop orange peel and lemon peel. Add.
Stir in honey, kirsch, and egg white until stiff.
Knead the dough into a ball. Roll it out to 7 mm (maximum) on powdered sugar.
Cut out small rectangles (or keep a large rectangle) and arrange on a buttered baking sheet (or on baking paper).
Let dry overnight.
Bake for 10-15 minutes in the middle of the oven preheated to 180°C.
Decorate as desired (icing: 50 g confectioners' sugar and 1⁄2 tbsp water.)