Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish.
In a large mixing bowl, combine the cooked egg noodles, shredded chicken, frozen mixed vegetables, cream of chicken soup, sour cream, garlic powder, onion powder, black pepper, and salt. Stir until well combined.
Pour the mixture into the prepared baking dish and spread it evenly.
In a small bowl, mix the breadcrumbs with the melted butter until the crumbs are evenly coated. Sprinkle the breadcrumb mixture over the top of the casserole.
Bake in the preheated oven for 25-30 minutes, or until the casserole is bubbly and the top is golden brown.
Remove from the oven and let it cool for 5 minutes before serving.