Preheat your oven to 350°F (175°C) to ensure even cooking.

Heat 1 tablespoon of olive oil in a skillet over medium heat. Sauté diced yellow onion until tender and translucent, about 10 minutes.

In a large mixing bowl, combine ground beef, bread crumbs, eggs, whole milk, salt, black pepper, onion powder, garlic powder, Italian seasoning, half of the ketchup, Worcestershire sauce, and sautéed onions.

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

Mix remaining ketchup with brown sugar in a small bowl and spoon it over the formed meatloaf.

Cover the meatloaf loosely with aluminum foil and bake for 45-60 minutes until the internal temperature is 160°F (71°C).

Remove foil during the last 10-15 minutes of baking for caramelization. Let it rest for 10-15 minutes before slicing.

Slice the meatloaf into thick pieces and serve warm with side dishes.