Bring a large pot of water to a boil. Add 1/2 teaspoon salt and pasta, and cook until al dente, about 8 to 10 minutes; drain.
Meanwhile, in a large bowl, stir together mushroom soup, sour cream, chicken, and peas. Season with garlic powder, onion powder, 1/2 teaspoon salt, and pepper.
Stir cooked pasta into chicken mixture until well combined. Pour pasta mixture into a 9x10-inch casserole dish, and spread out evenly. Top with Parmesan cheese, and spray the top with a bit of cooking spray.
Bake in a preheated oven until golden brown, about 20 to 25 minutes. Remove from oven, and let cool 5 minutes.