1. In a skillet over medium heat, cook the ground turkey sausage until browned and fully cooked, breaking it into small crumbles. Remove the sausage from the skillet and set it aside.
2. In the same skillet, melt the butter over medium heat, then whisk in the flour to form a smooth roux. Cook for 1-2 minutes until lightly golden.
3. Gradually pour in the milk, whisking continuously to prevent lumps, and cook until the mixture thickens into a creamy sauce.
4. Add the garlic powder, onion powder, salt, and black pepper to the gravy, stirring to combine. Adjust seasoning as needed.
5. Stir the cooked sausage back into the gravy and simmer for 2-3 minutes to blend flavors.
6. Slice the biscuits in half and spoon the sausage gravy generously over the bottom half. Place the top half of the biscuit on top or serve open-faced.
7. Garnish with chopped parsley if desired, and serve warm.