Preheat oven to 180 C (375 F). Line a few baking sheets with baking parchment or grease proof liners. Combine the flour, cocoa powder, ground ginger, ground cloves, bicarbonate of soda, caster sugar and brown sugar in the bowl of a food processor. Pulse a few times to combine all of the ingredients. Now add the cold butter and pulse until the mixture is like fine sand. Stop before the mixture starts to make clumps. Add the egg and the treacle and mix until just combined, adding enough water to make a dough which will come away in a ball inside the food processor bowl. If the dough is too wet, add a little more flour until it comes into a ball. If it's too dry and crumbly add a little more water. Remove the dough from the food processor and lightly knead until the dough is pliable and holds together. Flatten into a disc and wrap in clingfilm. Refrigerate until ready to use. The dough is best if left to mature for a day or two in the fridge. To roll out the dough, dust your work surface with gluten free flour. Divide the dough into thirds and roll out one third of the dough at a time. You can roll the dough out thin, if you like your biscuits crisp or keep them a little thicker if you prefer the traditional gingerbread texture. Cut into decorative shapes and place on the lined baking trays. Bake 8- 10 minutes until just set. Leave to cool on a wire rack before decorating.
If you can't get treacle, you can substitute molasses, dark corn syrup, golden syrup or honey in the same quantities as stated.