In a medium saucepan, gently heat 1 cup of water, ¾ cup of sugar, and ¼ cup of honey over medium-low heat until the sugar dissolves. Remove from heat and let cool slightly for about 10 minutes.

In a large mixing bowl, blend together 2 cups of flour, ½ cup of mixed candied citrus peel, ½ cup of toasted, ground hazelnuts, ¼ cup of unsweetened cocoa powder, zest of one lemon, 2 tsp of German Lebkuchen spice mix, 1 tsp of ground cinnamon, ½ tsp of fine sea salt, ½ tsp of baking soda, and 1 tsp of baking powder. Whisk until combined.

Add the honey mixture to the dry ingredients along with 1 large egg and ½ cup of milk. Mix until a stiff dough forms, about 2-3 minutes.

Wrap the dough tightly in plastic wrap and refrigerate for at least 12 hours or up to 3-5 days.

Preheat your oven to 350°F (180°C) and line a baking sheet with parchment paper. Shape the chilled dough into ¾-inch thick ropes, about 11 inches long, and arrange them on the baking sheet, flattening slightly.

Bake in the preheated oven for 12-14 minutes until puffy and soft. Cool on the baking sheet for a few minutes before transferring to a wire rack.

Whisk together 1 cup of icing sugar, 2 tbsp of cocoa powder, and the juice of ½ lemon in a small bowl. Add water slowly to reach a smooth, pourable consistency for the glaze.

Once cooled, brush the warm cookies with glaze, let set for a few minutes, then slice into diamond shapes.