Preheat oven to 375° F. Line a rimmed baking sheet with aluminum foil. Grease the foil with olive oil or spray with cooking spray.
Heat the 1 tablespoon olive oil in a skillet over medium heat. Add the onion and cook until softened, 3-4 minutes. Add the garlic and cook, stirring, for 30 seconds. Remove pan from the heat.
In a large bowl, combine the egg, ketchup, Worcestershire sauce, Italian seasoning, garlic powder, salt and pepper. Stir until the ingredients are well combined.
Stir in the sautéed onion and garlic.
Add the breadcrumbs and ground turkey. Mix with your hands until everything is just combined; do not overmix.
Transfer the meat mixture to prepared baking sheet and use your hands to shape it into a loaf shape, about 6 inches long, 4½ inches wide and 1½ inches tall.
In a small bowl, whisk together the glaze ingredients: ketchup, brown sugar and apple cider vinegar. Brush the glaze over the top of the meatloaf.
Bake for 45-60 minutes, until the internal temperature in the center of the meatloaf registers at least 165° F on an instant read thermometer. Let the meatloaf rest for 10 minutes. Then transfer to a serving platter or cutting board, slice and serve.