Preheat oven to 350°F and grease a 10-inch square baking dish with nonstick spray.
Cook noodles according to package directions. Drain and place in a large bowl.
Add chicken, sour cream, soup, garlic powder, and cheese to noodles and stir to combine.
Transfer to prepared baking dish, and bake until golden brown and bubbly, about 25 minutes. Top with fried onions and return to oven until browned, 5-10 more minutes.
