Preheat the oven to 350°F (175°C).

In a large mixing bowl, combine cooked chicken, egg noodles, and peas and carrots.

In a separate bowl, whisk together cream of mushroom soup, cream of chicken soup, milk, sour cream, black pepper, and garlic powder until smooth.

Pour the creamy sauce over the chicken and noodle mixture, then fold gently to combine.

Grease a 9x13-inch baking dish and pour in the combined mixture, spreading evenly.

Sprinkle cheddar cheese on top, and add crushed crackers or breadcrumbs if desired.

Cover with aluminum foil and bake for 20 minutes, then uncover and bake for an additional 10-15 minutes until golden brown.

Let cool for 5-10 minutes before serving.