Reserve 2/3 cup of the mozzarella cheese for the top layer of the lasagna. In a medium size bowl, combine remaining 1 1/3 cup mozzarella, soup and milk and set aside. In another medium size bowl, combine spinach, egg and ricotta. Mix well, then combine with soup mixture and mix all together.
In the bottom of a 13x9 inch baking dish, spread 1/3 of the mixture. Spread 1/3 of the chicken over the mixture and arrange 4 lasagna noodles over mixture and repeat. Top with remaining 1/3 of mixture, chicken, noodles and reserved 2/3 cup mozzarella cheese and Parmesan cheese.
Bake at 350 degrees F (175 degrees C) for 40 minutes or until hot and bubbling. Let stand 15 minutes before serving.