Preheat oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish.
In the baking dish, mix together uncooked pasta, diced raw chicken, marinara sauce, water or broth, garlic powder, Italian seasoning, salt, and pepper. Stir until well combined.
Cover tightly with foil and bake for 35 minutes.
Remove foil, sprinkle mozzarella and Parmesan evenly over the top.
Bake uncovered for an additional 10-15 minutes, or until pasta is tender and cheese is bubbly and golden.
Let sit for 5 minutes before serving. Garnish with fresh herbs if desired.