In a large bowl, combine cooked chicken, egg noodles, butter, cream of chicken soup, sour cream, garlic powder, and black pepper. Mix until everything is evenly combined.
Spread the mixture into a greased 9x13-inch baking dish.
Bake for 25 minutes, or until the top is lightly browned and the noodles are cooked through.
Sprinkle the cheddar cheese over the top of the casserole, and bake for an additional 10 minutes.
Serve hot and enjoy!
Interesting Facts
This dish is a great way to use up leftover cooked chicken.
The casserole can be made ahead of time and refrigerated or frozen for later use.
For added crunch, top the casserole with crushed potato chips before baking.