In a large bowl, add cooked chicken, cream of chicken soup, cream of mushroom soup, milk, chicken broth, onion powder, and garlic powder. Stir until combined. Add in uncooked pasta and stir until combined.
Pour into the prepared baking dish. Cover and refrigerate overnight.
Remove from refrigerator and uncover.
Preheat oven to 350 degrees.
Sprinkle with grated parmesan. Bake at 350 degrees, uncovered, for 1 hour.