Preheat your oven to 450°F. In a large mixing bowl, whisk together the flour, baking powder, and salt. Add the cold, cubed butter and use a pastry cutter or your fingertips to work the butter into the flour until the mixture resembles coarse crumbs. Pour in the milk and stir gently until the dough just comes together. Turn the dough out onto a lightly floured surface and pat it into a rectangle about 1 inch thick. Use a biscuit cutter or a glass to cut out rounds. Place them on a baking sheet and bake for 12-15 minutes, until golden brown on top.

While the biscuits bake, heat a large skillet over medium heat. Add the breakfast sausage and cook, breaking it up with a wooden spoon, until it's browned and cooked through, about 5-7 minutes. Don't drain the fat.

Sprinkle the flour evenly over the cooked sausage. Stir constantly for about 1-2 minutes. Gradually pour in the milk, stirring continuously to prevent lumps. Bring the mixture to a gentle simmer, stirring often. Season with black pepper and salt, tasting as you go.

Split your warm biscuits in half and place them on serving plates. Ladle the hot, creamy sausage gravy generously over the top. Serve immediately.