Preheat the oven to 350°F with a rack in the center position. Line a rimmed sheet pan with parchment paper or foil.
Heat the olive oil in a large skillet over medium heat. Once the oil is glistening, add the onion and cook, stirring often, until softened, about 5 minutes. Add the garlic and cook, stirring, until fragrant, about 1 minute more.
In a small bowl, combine the brown sugar, 1 tablespoon Worcestershire, and 1 tablespoon tomato paste until smooth.
In a large bowl, combine the turkey, onion mixture, bread crumbs, milk, remaining 2 tablespoons tomato paste, Italian seasoning, cayenne, garlic powder, onion powder, remaining 2 tablespoons Worcestershire, eggs, salt, and pepper. Mix well, then with wet hands, form into a loaf on the prepared sheet pan. Using a pastry brush, rub the meatloaf all over with the brown sugar mixture.
Bake until the internal temperature reaches 165°F on an instant-read thermometer, about 50 minutes.
Remove and let rest for 10 minutes. Slice the meatloaf and serve.