Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the flour, baking powder, salt, and baking soda. Whisk until well mixed.
Add the cold cubed butter to the flour mixture. Using your fingers or a pastry cutter, mix until the mixture resembles coarse crumbs.
Pour in the buttermilk and stir gently just until the dough comes together. Do not over-mix.
Turn the dough out onto a floured surface. Pat the dough into a 1-inch thick rectangle. Fold the dough over itself 2-3 times to create layers, then cut out biscuits using a round cutter. Place them on the prepared baking sheet.
Bake the biscuits in the preheated oven for 12-15 minutes until golden brown.
While the biscuits are baking, cook the sausage in a large skillet over medium heat, breaking it up with a spoon until fully browned and crispy.
Once the sausage is browned, sprinkle 3 tablespoons of flour over the meat and stir to combine, cooking for an additional minute.
Gradually whisk in the milk, stirring constantly until the mixture thickens into a creamy gravy. Season with salt and black pepper to taste.
Remove the biscuits from the oven and split them in half. Serve generously topped with the sausage gravy.
Notes
Garnish with freshly chopped parsley and serve the biscuits and gravy on a rustic wooden board for a cozy visual appeal.