Preheat oven to 450°F and line a baking sheet with parchment paper.
In a large bowl, whisk together 2 cups flour, baking powder, and 1 teaspoon salt.
Cut in cold butter using a pastry cutter or fork until mixture resembles coarse crumbs.
Pour in buttermilk and stir just until dough comes together, then turn onto floured surface and pat to 3/4-inch thickness.
Cut out biscuits using a 2-inch round cutter and place on prepared baking sheet, bake 12-15 minutes until golden brown.
While biscuits bake, brown sausage in a large skillet over medium-high heat, breaking it into small pieces.
Sprinkle 1/3 cup flour over cooked sausage and stir for 2 minutes.
Gradually pour in milk, stirring constantly, and cook until gravy thickens, about 5-7 minutes, then season with black pepper and salt.
Split warm biscuits in half and smother with sausage gravy.