Preheat the oven to 350F. Grease a large baking sheet with non-stick cooking spray; set aside.
In a large mixing bowl, combine the cheddar cheese, milk, onion, quick oats, egg, salt, and pepper. Add the ground beef and mix in very well.
1 cup cheddar cheese, ¾ cup milk, ½ cup onion, ½ cup quick oats, 1 egg, ½ teaspoon salt, ½ teaspoon pepper, 1- pound lean ground beef
Form the meat mixture into 8 small loaves and place on the prepared baking sheet.
In a small bowl, combine the ketchup, brown sugar, and mustard. Spoon the sauce over the meatloaves, covering the whole top and sides with the sauce.
2/3 cup ketchup, ½ cup brown sugar, 1 tablespoon yellow mustard
Bake the meatloaves at 350F for 25-30 minutes, or until the center is no longer pink and the internal temperature reaches 160F.
Serve the meatloaves hot.