1Preheat oven to 400°F. Spray a 9x13-inch baking dish with nonstick cooking spray.
2Place uncooked noodles into the baking dish and top evenly with undrained tuna; set aside.
3In a microwave-safe bowl, combine water, cream cheese spread, Parmesan cheese, salt, and pepper. Microwave on high for 2 minutes. Stir well and microwave for 2 additional minutes or until boiling.
4Carefully pour hot cheese mixture over tuna and noodles in baking dish.
5Cover dish tightly with aluminum foil and bake at 400°F for 15 minutes.
6Remove from oven and stir frozen peas into noodle and cheese mixture. Sprinkle with cheddar cheese and cover again with foil. Bake for 15 minutes more or until noodles are tender.