Preheat the oven to 350°F (175°C).

Finely chop the onion and set it aside.

In a large mixing bowl, combine the ground beef and ground pork.

Mix in the breadcrumbs, milk, onion, ketchup, eggs, Worcestershire sauce, salt, pepper, garlic powder, Italian seasoning, and brown sugar.

Using your hands or a spoon, mix everything until just combined.

Transfer the mixture to a loaf pan and shape it into a loaf.

Bake in the preheated oven for about 1 hour or until the internal temperature reaches 160°F (70°C).

Once cooked, remove it from the oven and let it rest for 10 minutes.

Carefully slice the meatloaf and serve it warm.