Preheat the oven to 350 degrees F. Grease a 9x5 in loaf pan and set aside.
In a large bowl, combine all ingredients except ketchup. Mix together until well incorporated, but don't overmix.
Transfer the mixture into the loaf pan. Bake for 30 minutes.
Spread the ketchup on top of the meatloaf (if using). Return to the oven and bake for 25-45 more minutes, until cooked through and internal temperature reaches 160 degrees F. (Time will vary depending on thickness of the loaf.).