Pre-heat your oven to 425. Use a whisk to mix the gluten-free flour, xanthan gum, sea salt, and baking powder in a mixing bowl.
Cut the butter into small cubes and “cut” into the mix using either a pastry cutter or a fork. Make sure you don’t leave any chunks of butter in the mix. You want it as blended as possible.
Add milk and mix together with a large wooden spoon. Make sure all of the flour mix is soaked up. Form the dough into a ball and knead a few times.
Lay out parchment paper and sprinkle some gluten-free flour on it.
Use a rolling pin to roll out the dough on the parchment paper so that the dough is about 2” thick.
Use a biscuit cutter or mason jar to cut out the biscuits. I like mine super thick because they fluff up more. I’ve made them thinner, and it was hard to split them open after they were baked.
Put your cut out biscuits on an ungreased baking tray and put in the fridge for 30 minutes.
After they’ve chilled for half an hour, bake the biscuits for 12-15 minutes. I like to set a timer for halfway and rotate them in the oven to be sure they cook evenly. The longer you bake them, the more golden and “crispy” they’ll be. You do not want them too crispy or they won't be as flaky. I live at altitude, and 15 minutes is the sweet spot.