Heat oven to 450°F; line a baking sheet with parchment.
Whisk 2 cups flour, baking powder, and 1 teaspoon salt in a large bowl.
Cut in cold butter with a pastry cutter or fork until coarse crumbs form.
Stir in buttermilk just until dough forms; turn onto a floured surface and pat 3/4-inch thick.
Cut with a 2-inch round cutter; place on prepared sheet and bake 12-15 minutes until golden brown.
Meanwhile, brown sausage in a large skillet over medium-high heat, breaking into small pieces.
Sprinkle 1/3 cup flour over cooked sausage; stir 2 minutes.
Gradually stir in milk; cook, stirring constantly, until thickened, about 5-7 minutes. Season with pepper and salt.
Split warm biscuits; cover with gravy.