Preheat your oven to 350°F (175°C).
Sauté the chopped onion in a skillet over medium heat until translucent (about 5 minutes).
In a large bowl, combine ground beef, breadcrumbs, sautéed onions, egg, Worcestershire sauce, and half of the ketchup. Mix gently until just combined.
Shape the mixture into a loaf and place it in a baking dish.
In a small bowl, mix remaining ketchup with brown sugar. Spread over the meatloaf.
Bake for about 1 hour or until the internal temperature reaches 160°F (70°C). Let rest before slicing.
