Set your oven to 350°F (175°C). Lightly grease a 9×5-inch loaf pan or line a baking sheet with foil.

In a large bowl, combine ground beef, chopped onion, eggs, milk, breadcrumbs, minced garlic, 1/4 cup ketchup, parsley, Worcestershire sauce, salt, pepper, and Italian seasoning. Gently mix until ingredients are well incorporated but avoid overmixing.

Form the meat mixture into a loaf shape and place it into the prepared loaf pan or onto the lined baking sheet.

In a small bowl, mix 1/2 cup ketchup, brown sugar, vinegar, garlic powder, and onion powder to make the glaze.

Brush half of the glaze evenly over the top of the meatloaf.

Bake in the preheated oven for 45 minutes.

Brush the remaining glaze over the meatloaf and continue baking for an additional 15-30 minutes.

Ensure the internal temperature reaches 160°F (71°C).

Remove the meatloaf from the oven and let it rest for 10-15 minutes before slicing.

Slice the meatloaf into portions and serve warm.