Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish.
Cook Noodles:
Cook the egg noodles according to package instructions until al dente. Drain and set aside.
Prepare the Sauce:
In a large bowl, combine the cream of chicken soup, cream of mushroom soup, sour cream, and milk. Stir until well mixed.
Combine Ingredients:
Add the cooked chicken, cooked noodles, peas and carrots, Parmesan cheese, garlic powder, onion powder, salt, and pepper to the sauce mixture. Stir until everything is evenly coated.
Assemble the Casserole:
Pour the mixture into the prepared baking dish. Sprinkle the shredded cheddar cheese evenly over the top.
Prepare the Topping:
In a small bowl, mix the crushed Ritz crackers or bread crumbs with the melted butter. Sprinkle this mixture evenly over the casserole.
Bake:
Bake in the preheated oven for 30-35 minutes, or until the casserole is bubbly and the top is golden brown.
Serve:
Remove from the oven and let it cool slightly. Garnish with chopped fresh parsley, if desired, before serving.