Begin by preheating your oven to 350 degrees F (175 degrees C). Lightly coat a 9x13-inch baking dish with cooking spray or oil.

In a large mixing bowl, combine the shredded cheese, milk, oats, egg, and salt. Stir until well incorporated. Gradually add the ground beef, mixing until the ingredients are evenly blended. Shape the mixture into eight mini loaves and place them in the prepared baking dish.

In a separate small bowl, mix together the ketchup, brown sugar, and mustard. Stir thoroughly until smooth, then generously spread this glaze over the tops of each meatloaf.

Bake the mini meatloaves, uncovered, for approximately 45 minutes. To ensure they are fully cooked, use an instant-read thermometer to check that the internal temperature reaches at least 160 degrees F (72 degrees C).