Boil the eggs for 10-12 minutes until hard, then rinse with cold water and peel. Halve the eggs, remove the egg yolk and pass through a fine sieve into a mixing bowl. Mix with 1 raw egg yolk and sieved icing sugar.
Add fat, lemon peel and gingerbread spice and stir until creamy. Add flour and work vigorously with the dough hooks of the hand mixer. Quickly work into a smooth dough with cool hands, cover and chill for about 30 minutes.
Roll out the dough on a work surface sprinkled with flour to a thickness of approx. 1 cm and cut into sticks approx. 1 cm wide and 8 cm long. Press 3 hazelnuts onto each strip of dough. Place on a baking tray lined with baking paper.
Whisk the rest of the egg yolk and 1 teaspoon of water and brush the sticks with it. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for 12-15 minutes. Results in about 80 pieces.