Preheat oven to 350°F. Spray a foil lined baking tray with cooking spray and set aside.
In a medium bowl combine eggs, milk, and breadcrumbs. Allow mixture to sit for 5-10 minutes.
Add the ground beef, onions, 1 tablespoon of chili sauce, Italian seasoning and parsley. Mix until just combined.
Form a 8"x4" loaf on the prepared baking tray. Bake for 40 minutes.
Meanwhile, combine the chili sauce and ketchup (and brown sugar if using). Spread mixture over the meatloaf and bake for an additional 10-15 minutes or until cooked through and the meatloaf reaches 160°F.
Allow meatloaf to rest for 10 minutes before slicing.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)