Preheat oven to 400°F.
In a large pot over medium heat, combine milk, cream of bacon soup, cream cheese, salt, pepper, garlic powder and onion powder. Stir well until smooth and heated through.
Once mixture comes to a boil, add spaghetti and cook for 8 minutes, stirring occasionally.
Stir in 2 cups mozzarella cheese and 1/2 cup bacon bits.
Transfer spaghetti mixture to a greased 9x13 baking dish. Spread evenly.
Top with remaining 2 cups mozzarella, chives, and 1/2 cup bacon bits.
Bake for 14-15 minutes until cheese is melted and bubbling.
Let sit 5 minutes before serving.