Preheat oven to 425F and line a baking sheet with parchment paper. Whisk together gluten free flour, baking powder, and salt. Cut in cold butter until the mixture resembles coarse crumbs. Stir in cold buttermilk until a shaggy dough forms.
Drop the dough in 8 equal mounds onto the prepared baking sheet. Bake for 14 to 16 minutes until the tops are golden brown and the biscuits are cooked through.
While the biscuits bake, cook the breakfast sausage in a large skillet over medium heat, breaking it into crumbles, until fully browned and no pink remains, about 6 to 8 minutes.
Sprinkle gluten free flour over the cooked sausage and stir for 1 minute. Slowly pour in milk while stirring constantly. Add salt, pepper, and garlic powder. Cook, stirring often, until the gravy thickens, about 4 to 5 minutes.
Split the warm biscuits in half and place on plates. Ladle the sausage gravy generously over the top and serve immediately.