Preheat your oven to 350°F (175°C). Line a rimmed baking sheet with parchment paper or lightly grease a loaf pan if using.
In a large mixing bowl, combine the ground beef, diced onion, minced garlic, eggs, ketchup, Worcestershire sauce, oats, milk, parsley, Italian seasoning, salt, and pepper. Using your hands or a large spoon, gently mix until everything is just incorporated. Avoid over-mixing, as this can lead to a dense texture.
Shape the mixture into a loaf about 9x5 inches on the prepared baking sheet, or press it into your loaf pan.
In a small bowl, stir together the ketchup, Worcestershire sauce, and coconut sugar to create the glaze. Spread this evenly over the top of your meatloaf for a glossy, flavorful coating.
Bake the meatloaf in the preheated oven for 50-60 minutes, or until the internal temperature reads 160°F (70°C) on a meat thermometer. The top should be slightly caramelized.
Let the meatloaf rest on the baking sheet for 10 minutes before slicing. This helps retain the juiciness of the meatloaf. Enjoy warm!