Prepare by getting a mixer with bread kneading pins ready and lining a baking tray with baking paper and starting to pre-heat your oven to 190 degrees Celsius. Measure the sugar, butter and gluten-free flour into separate bowls, using a large bowl for the butter.
In the bowl you have you butter in, chop the butter into smaller pieces then pour over the sugar and use the mixer to blend the two together into a paste. Now gradually add the flour to the mix and continue to mix a good 4 to 5 minutes after all the flour is in. Once that is done, use your hands to knead the mix together into a large mass and once you have this turn it out onto a kitchen surface.
Use a rolling pin to roll the mass out into a square-ish shape, approximately 5 millimetres thick, then trim the edges so you have a square. Use a fork to press holes into the mass in a line, starting the second next to where the first line is. Once you have finished, use a knife to cut a gap between each line of fork marks vertically, then cut the lines into small biscuits horizontally.
Use a cake slice to remove the biscuits (one by one) and put them onto the baking tray, leaving a good 5-10 millimetre gap between each as they spread out when baking. Now bake in the oven for 15-20 minutes and when done leave to cool until fully cooled so they firm up.