1. Preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish.

2. In a large skillet over medium heat, cook the breakfast sausage, breaking it into small crumbles, until fully browned with no pink remaining. Do not drain all of the drippings.

3. Add the unsalted butter to the skillet with the cooked sausage and let it melt, stirring to combine with the drippings.

4. Sprinkle the all-purpose flour evenly over the sausage mixture and cook, stirring constantly, for 1–2 minutes to form a roux.

5. Slowly pour in the milk while whisking or stirring, working out any lumps, and bring the mixture to a gentle simmer.

6. Continue to cook, stirring frequently, until the gravy thickens to a creamy, spoonable consistency, about 5–7 minutes.

7. Season the gravy with salt, black pepper, garlic powder, onion powder, and crushed red pepper flakes if using, then taste and adjust seasoning as needed.

8. Pour the sausage gravy into the prepared baking dish and spread it into an even layer.

9. Open the can of refrigerated biscuit dough and cut each biscuit into four pieces (or slightly smaller if they are very large).

10. Arrange the biscuit pieces evenly over the top of the gravy, leaving a little space between each piece so they can puff up as they bake.

11. Brush the tops of the biscuit pieces lightly with melted butter if desired for extra color and flavor.

12. Bake the casserole for 20–25 minutes, or until the biscuits are puffed and deeply golden brown and the gravy is bubbling around the edges.

13. Remove the dish from the oven and let the casserole rest for 5–10 minutes so the gravy can set slightly before serving.

14. Scoop into bowls or onto plates and serve warm, optionally garnished with chopped fresh parsley or chives.