Preheat your oven to 350°F (175°C).
Cook the egg noodles according to package instructions until al dente, then drain and set aside.
In a large mixing bowl, combine the cooked turkey, cooked egg noodles, frozen mixed vegetables, cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper. Mix until well combined.
Transfer the mixture into a greased 9x13-inch baking dish.
In a small bowl, mix the breadcrumbs with the melted butter until evenly coated. Sprinkle the breadcrumb mixture over the casserole.
Bake in the preheated oven for 25-30 minutes, or until the casserole is bubbly and the top is golden brown.
Let it cool for 5 minutes before serving.