01 -
Line a rimmed baking sheet with parchment paper or foil to facilitate cleanup, then preheat the oven to 350°F.
02 -
Heat 1 tsp olive oil in a medium skillet over medium heat. Add the chopped onion and cook, stirring occasionally, until softened and golden, about 5 to 7 minutes. Remove from heat and set aside to cool.
03 -
In a large bowl, combine ground beef, sautéed onions, eggs, minced garlic, ketchup, fresh parsley, breadcrumbs, milk, salt, Italian seasoning, and black pepper. Mix until just combined, avoiding overmixing to prevent a dense texture.
04 -
Transfer the meat mixture to the prepared baking sheet and shape into a loaf approximately 8 inches long, 4 inches wide, and 3 inches tall. Bake uncovered at 350°F for 40 minutes.
05 -
In a small bowl, whisk together ketchup, white vinegar, brown sugar, garlic powder, and onion powder until smooth.
06 -
Spread the prepared glaze evenly over the partially baked meatloaf. Return it to the oven and bake an additional 20 minutes, or until the internal temperature reaches 160°F. Let rest for 10 to 15 minutes before slicing for easier serving.