Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.
In a large bowl, combine the condensed soup and whole milk. Stir until smooth. Add garlic powder, onion powder, salt, and pepper, mix well.
To the bowl with the sauce, add the cooked egg noodles, frozen mixed vegetables, shredded chicken, and 1 cup of shredded cheddar cheese. Stir until all ingredients are well incorporated.
Pour the noodle and chicken mixture into the dish into the prepared baking dish, spreading it evenly.
In a separate bowl, combine the plain bread crumbs with the melted butter. Stir until the crumbs are evenly coated
Sprinkle the remaining ½ cup of shredded cheddar cheese over the noodle mixture in the baking dish. Then, evenly distribute the buttery bread crumbs on top.
Place the casserole in the preheated oven and bake for 25-30 minutes, or until the topping is golden brown and the casserole is bubbly.
Once baked, remove the casserole from the oven and allow it to cool for a few minutes. Garnish with parsley if desired. Serve warm and enjoy!