Preheat oven to 350* and lightly grease/spray a loaf pan to prepare.
In a medium bowl, combine the ground beef, oats, milk, egg, onion, salt, and pepper. Wash hands first, then use hands to mix everything together well.
Transfer meat mixture to prepared loaf pan and spread evenly.
In a small bowl, combine ketchup, brown sugar, and mustard until smooth. Pour evenly over the meatloaf mixture in loaf pan.
Place in preheated oven and cook for approx 1 hr or until meatloaf is done in the center.
Remove from oven and let stand for about 5 minutes before serving. ENJOY!
