Add the sausage and onion powder into a large skillet and fry, breaking up all the chunks. Season this with salt and pepper cooking until the sausage is browned.
1 pound ground breakfast sausage, ½ teaspoon onion powder, ½ teaspoon salt, ¼ teaspoon ground black pepper
Preheat the oven to 350°F and grease a 7x11-inch baking dish with nonstick spray.
Add the quartered biscuits on the bottom of the baking dish.
12 ounces refrigerated biscuits
Spoon the seasoned sausage out of the pan and layer over the biscuits. (leave the grease and a little bit of sausage in the pan to make the gravy later).
Sprinkle shredded cheese over this.
1½ cups shredded cheddar cheese
In a separate bowl, break the eggs. Whisk together with milk and brown sugar. Pour this mixture over the top of the cheese.
6 large eggs, ½ cup whole milk, 1 Tablespoon light brown sugar
In the greased skillet, melt the butter over medium heat. Stir in the flour and allow this to cook for at least 3 minutes.
3 Tablespoons salted butter, 3 Tablespoons all-purpose flour
Whisk in the salt, pepper, thyme, and milk (slowly). Heat this on medium heat until thickened.
2 cups whole milk, 1 teaspoon salt, 1 teaspoon ground black pepper, ½ teaspoon dried thyme
Pour the gravy over the casserole.
Bake for 35 to 40 minutes. If biscuits and eggs are not fully cooked, continue baking for 5 more minutes at a time.