Pre-heat oven to 170˚C Fan / 190˚C / 375˚F.
Soften the dairy free butter in a mixing bowl.
Add the sugar to the bowl and mix lightly until just combined.
Sift the flour into the bowl with the sugar and butter, then add the cornflour, vanilla extract and xanthan gum.
Stir the mixture. It will feel very crumbly for a few minutes, this is totally normal, just keep going.
Once you have mixed for a few minutes, start bringing the mixture together with your hands into a ball.
Cut two squares of baking parchment/greaseproof paper and place the dough mixture in between the two sheets. (This stops you having to spread flour on your kitchen counter and making a mess when rolling out the mixture and also stops the mixture sticking to the rolling pin)
Roll out the dough to around 0.5cm thick using a rolling pin and then cut out the biscuits using a cookie cutter.
Place one of the greaseproof paper sheets on a baking tray and put the biscuits on the tray. You can use a fork to make a few holes in the middle of each biscuit for decoration and to let the steam escape If you want to add a little more sweetness and some crunch, sprinkle each biscuit with some sugar.
Bake in a hot oven for 18-20 minutes. The cookies should still have a pale colour when you remove them from the oven.