Preheat oven to 350°F (175°C).
In a large bowl, mix the turkey, noodles, vegetables, cream of chicken soup, milk, sour cream, garlic powder, onion powder, salt, and pepper.
Spread the mixture evenly into a greased 9x13-inch baking dish.
Top with shredded cheddar cheese.
In a small bowl, mix breadcrumbs with melted butter and sprinkle over the casserole.
Bake uncovered for 30-35 minutes or until bubbly and golden brown on top.
Let sit for 5 minutes before serving.