Preheat the oven to 400°F and line a large baking sheet with parchment paper.
In a food processor, combine the flour, baking powder, baking soda, and salt. Pulse until well mixed.
Add the chilled, cubed butter to the processor. Pulse until the mixture resembles coarse crumbs.
Pour in the buttermilk and pulse just until the dough comes together. Avoid over-mixing.
Transfer the dough to a floured surface. Roll it out, fold it over, and roll again to create layers.
Cut out biscuits using a round cutter. Place them on the prepared baking sheet.
Brush the tops with buttermilk and bake for 12-15 minutes, or until golden brown.
As the biscuits bake, cook the sausage in a skillet over medium heat until thoroughly browned.
Add the butter to the cooked sausage and stir until it melts completely for enhanced flavor.
Sprinkle flour over the sausage in the skillet. Stir and cook for about 2 minutes for the roux.
Gradually add the milk and optional vinegar, stirring consistently until smooth.
Season the gravy with black pepper, seasoned salt, and garlic powder to taste.
Let the gravy simmer for at least 5 minutes to thicken slightly before serving.
Spoon the gravy generously over the baked biscuits and enjoy warm.