In a mixing bowl, sift together the flour, bicarbonate of soda, ginger, mixed spice and salt.
Add the demerara sugar, then rub the diced butter into the flour mixture until it resembles breadcrumbs.
Add the golden syrup and chopped stem ginger to the bowl.
Mix in just enough ginger syrup to bring the dough together into a ball.
Wrap the dough in cling film and chill in the refrigerator for 1 hour.
Preheat the oven to 180°c/160°c fan and line 2 baking trays with parchment paper.
On a floured surface, roll out the biscuit dough to about 1cm thickness and use a round cutter to stamp out biscuits.
Place the biscuits on the prepared trays and bake in the preheated oven for about 25 minutes, or until golden-brown.
Leave the biscuits on the trays for 15 minutes to firm up before transferring them to a cooling rack to cool completely.
Dip each biscuit a third of the way into the melted chocolate, letting the excess drip off and resting on parchment paper to set.
