Basler Läckerli are one of Switzerland's oldest and most famous specialities, originating from Basel. These biscuits are characterized by a firm yet chewy centre, a rich blend of spices and candied fruit, and are finished with a thin, crunchy sugar glaze.
In a saucepan, heat the honey and spices (do not boil). Remove from heat and let cool slightly.
In a large bowl, mix the flour, baking soda, chopped almonds, and candied peel.
Add the warm honey and, if using, Kirschwasser. Knead into a stiff, sticky dough.
Wrap the dough in film and let it rest at room temperature for 12 hours (ideally overnight).
Preheat the oven to 185 °C (365 °F).
Roll out the dough on a baking sheet lined with parchment paper into a rectangle approximately 1 cm thick (adjust size to your tray).
Bake for 20-25 minutes until the surface is golden brown but the centre is still soft.
While the Läckerli are baking, prepare the glaze by mixing icing sugar, lemon juice, and hot water until it forms a thick but liquid mixture.
Immediately after taking it out of the oven, evenly brush the hot sheet of biscuits with the glaze.
Cut into small rectangles (approx. 5 x 3 cm) while the biscuits are still warm and the glaze has not set.
Let cool completely. The biscuits will harden, but the inside should remain slightly chewy. Store in an airtight container.