In a medium saucepan, combine water, sugar, and honey over medium heat. Stir gently until the sugar dissolves completely.

In a large mixing bowl, whisk together flour, toasted ground hazelnuts, cocoa powder, Lebkuchen spice mix, cinnamon, baking soda, baking powder, and fine sea salt.

Once your syrup has cooled, add it to the bowl with dry ingredients, then crack in the large egg and pour in the milk. Mix until a stiff dough forms.

Wrap your cookie dough tightly in plastic wrap and refrigerate for at least 4 hours, or ideally overnight.

Preheat your oven to 350°F (180°C) and line baking sheets with parchment paper. Divide the chilled dough into 8 equal portions and roll each into a rope.

Bake the cookie ropes for 12-14 minutes until soft but slightly puffed, looking set to the touch.

While cookies are baking, whisk together icing sugar, cocoa powder, lemon juice, and water to achieve a smooth glaze consistency.

Once cookies cool for a few minutes, brush them with the prepared glaze generously to add sheen and sweetness.

After the glaze sets, cut the cookies into diamond shapes as desired and store in an airtight container.