Preheat oven to 350 degrees F. Line a small baking dish with aluminum foil and coat the foil with nonstick cooking spray, and set it aside.
Add the breadcrumbs and milk to a large bowl and stir until the crumbs are completely saturated. Set aside and allow the breadcrumbs to soak and soften for 10 minutes.
Meanwhile, heat the oil in a small skillet over MEDIUM-LOW heat. Add the onions and cooking, stirring, for about 2 to 3 minutes, to soften slightly. Add the garlic and sauté for an additional 30 seconds. Remove the skillet from the heat and set it aside.
After the breadcrumb mixture has rested for about 10 minutes, add the egg, ketchup, Worcestershire sauce, Italian seasoning, salt, and pepper. Stir to combine well. Crumble the beef over the top (break it apart with your hands into small chunks) and add the cooked and slightly cooled onions. Mix just until well combined (don’t overmix).
Shape the meatloaf mixture into a ball with your hands and plop it down in the center of the prepared pan. Use your hands to form it into a loaf. Bake for 20 minutes.
Meanwhile, combine the glaze ingredients in a small bowl. After the initial baking time, remove the meatloaf from the oven and spoon the glaze over the meatloaf, spreading it out evenly over the top with the back of the spoon.
Return the meatloaf to the oven and bake for an additional 20 to 25 minutes, or until the internal temperature is at least 165 degrees F in the center. Remove from the oven and allow it to rest for 10 minutes.
Use the foil overhang to lift the meatloaf out of the pan, then using a sturdy spatula, transfer the meatloaf to a cutting board and discard the foil. For the cleanest slices, allow it to rest about 5 to 10 minutes, then slice and serve.