Preheat the oven to 375°F (190°C). Lightly grease a 9x5-inch loaf pan with cooking spray.
Add the ground chicken, onion, garlic, breadcrumbs, Parmesan, milk, eggs, Italian seasoning, garlic powder, onion powder, salt, pepper, and Worcestershire sauce to a large mixing bowl.
Gently mix with clean hands or a wooden spoon until the ingredients are evenly combined. Avoid overmixing, as this can make the meatloaf dense.
Transfer the mixture to the prepared loaf pan and press it into an even loaf.
Whisk the ketchup, brown sugar, Dijon mustard, and Worcestershire sauce together in a small bowl. Spread about half of the glaze evenly over the top of the meatloaf, reserving the rest for later.
Bake for 40 minutes. Remove the meatloaf from the oven and spread the remaining glaze over the top. Sprinkle the shredded mozzarella evenly over the surface.
Return the meatloaf to the oven and bake for another 10 minutes, or until the cheese has melted and the chicken reaches a safe internal temperature of 165°F (74°C). Broil for 1 to 2 minutes at the end if you want a more golden cheese topping.
Let the meatloaf rest for about 10 minutes before slicing. Garnish with freshly grated Parmesan and chopped chives, then serve warm.