In a large mixing bowl, whisk together the gluten-free flour blend, baking powder, and salt until no lumps remain—this should take about 1-2 minutes.

Chop cold, unsalted butter into small cubes and add it to the flour mixture. Using your fingers, work the butter into the dry ingredients until the mixture resembles coarse crumbs, leaving some pea-sized butter pieces, about 3-4 minutes.

Pour in the milk all at once. Using a fork, gently mix the dough until it just comes together—about 30 seconds. Avoid overmixing.

Preheat your oven to 425°F (220°C) while preparing the baking sheet. Line it with parchment paper. Use a spoon to drop generous spoonfuls of the dough onto the lined sheet, leaving space between each mound.

Place the tray in the preheated oven and bake the biscuits for 12-15 minutes, until they are puffed up and golden brown on top.