Preheat oven to 350 degrees.

Spray a muffin tin with cooking spray.

In a skillet, brown the sausage and onion together until sausage is fully cooked. Drain off any excess grease and set aside.

Divide the hash browns evenly between the muffin cups.

Mix the sausage, cheese, and salt and pepper together. Divide mixture evenly between the muffin cups.

In a small bowl, whisk eggs and milk together. Divide egg mixture evenly between the muffin cups.

Bake at 350 degrees for 20 minutes. Makes 12 muffins.