In a skillet over medium heat, brown pork sausage until it reaches an internal temperature of 160°F.
Reduce the heat to medium-low and add flour to the skillet. Stir to combine and slowly pour in the milk. Stir frequently until the mixture thickens (about 10-12 minutes). Add salt, pepper, and garlic powder and set aside to cool slightly.
Preheat the oven to 375°F and prepare a 12-inch oven-safe skillet by spraying it with nonstick cooking spray.
Remove the biscuits from the can and place them on a clean work surface. Using a rolling pin, flatten each biscuit to about ⅛-inch thickness.
Place 2 heaping tablespoons of the sausage mixture on top of each flattened biscuit. Pinch the edges of the biscuit together to seal the mixture inside.
Place the sealed biscuits, seam-side down, in the prepared skillet. Optional: brush the tops with a mixture of melted butter, garlic salt, and parsley.
Bake for 18-20 minutes or until golden brown. Serve warm, topped with remaining gravy and garnished with parsley.