1. Preheat the oven to 450°F (230°C). Line a baking sheet with parchment paper.

2. In a large bowl, whisk together the flour, baking powder, baking soda, sugar, and salt for the biscuits.

3. Add the cold cubed butter to the dry ingredients. Cut it in with a pastry cutter or your fingertips until the mixture looks like coarse crumbs with pea-sized bits of butter.

4. Pour in the cold buttermilk and stir just until a soft dough forms. Do not overmix or the biscuits will be tough.

5. Turn the dough out onto a lightly floured surface. Gently pat it into a rectangle about 1 inch thick, fold it over on itself, then pat it out again. Repeat the folding once or twice to create flaky layers.

6. Pat the dough into a 1-inch-thick slab. Cut out biscuits with a round cutter or slice into squares. Place them close together on the prepared baking sheet.

7. Brush the tops lightly with extra buttermilk, then bake for 12–15 minutes, or until tall and golden brown.

8. While the biscuits bake, place the sausage in a large skillet over medium heat. Cook, breaking it into small crumbles, until browned and cooked through. Add the butter if the sausage is very lean and there isn’t much fat in the pan.

9. Sprinkle the flour over the sausage and drippings. Stir well to coat and cook for 1–2 minutes to remove the raw flour taste.

10. Slowly pour in the milk while stirring constantly, scraping up any browned bits from the bottom of the pan.

11. Add the garlic powder, onion powder, salt, black pepper, and crushed red pepper flakes if using. Continue to cook, stirring frequently, until the gravy thickens and gently bubbles. Adjust the seasoning to taste.

12. Split the warm biscuits in half and place them on plates. Spoon the hot sausage gravy generously over the biscuits and serve immediately with extra black pepper on top if desired.