Place the golden syrup, treacle, vegan butter and brown sugar in a pan. Heat gently until melted.
Remove from the heat and whisk in the ground almonds, milk, orange zest, baking powder, bicarbonate of soda, cinnamon, ginger, allspice, nutmeg, cloves, cardamom, coriander and salt.
Add the flour and stir to form a soft, sticky dough.
Scrape into a bowl and cover, or wrap the dough in baking parchment, and refrigerate for at least a couple of hours, ideally overnight, until the dough is firm.
Preheat the oven to 180°C/160°C fan/350°F/ gas mark 4. Line two baking sheets with baking parchment.
Roll the dough out on a lightly floured surface to 6-10mm thick, depending on how thick you want your lebkuchen to be. (Mine were about 7-8mm).
Use cutters to cut out as many cookies as possible. Place them well spaced apart on the baking sheets. Bring together the scraps of dough, re-roll and cut out more cookies.
Bake the lebkuchen for 10-15 minutes until they are lightly browned around the edges and the suface of the cookies no longer looks wet.
Allow to cool on the trays for a few minutes, then carefully transfer them to a wire rack to cool completely.
Once the lebkuchen have cooled, place the sifted icing sugar in a small bowl and stir in the lemon juice to form a runny glaze.
Dip the tops of the lebkuchen in the glaze or in melted chocolate, then place them on a wire rack until set. Once set store in an airtight container at room temperature.