Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking dish.

In a large pot, bring salted water to a boil and cook the egg noodles until al dente, about 6-8 minutes. Drain and set aside.

In a mixing bowl, combine the cream of chicken soup, sour cream, and milk, whisking until smooth. Stir in garlic powder, onion powder, salt, and black pepper.

Fold in the shredded chicken and half of the cheddar cheese until well-coated.

Gently fold the cooked egg noodles into the mixture, ensuring even coating.

Pour into the greased baking dish, top with remaining cheddar cheese and optionally bacon.

Cover with aluminum foil and bake for 20 minutes, then uncover and bake for an additional 10-15 minutes until cheese is bubbly.

Let the casserole rest for about 5 minutes before garnishing with chopped green onions and serving.