Preheat your oven to 350°F (175°C). Grease a 9×13 inch baking dish.
Prepare the Biscuits:Open the can of refrigerated biscuits and separate them. Cut each biscuit into quarters.
In a mixing bowl, toss the biscuit pieces with melted butter, garlic powder, and dried parsley until evenly coated.
Arrange the coated biscuit pieces in the prepared baking dish.
Prepare the Gravy:In a skillet over medium heat, cook the breakfast sausage, breaking it apart with a spatula, until browned and cooked through.
Sprinkle the cooked sausage with flour, stirring constantly for about 1 minute to cook off the raw flour taste.
Gradually pour in the milk, stirring constantly to prevent lumps from forming.
Continue cooking and stirring until the gravy thickens, about 5-7 minutes. Season with salt and pepper to taste.
Assemble the Casserole:Pour the prepared gravy evenly over the biscuit pieces in the baking dish, making sure all the biscuits are covered.
Use a spatula to gently mix the biscuits and gravy together, ensuring the biscuits are coated.
