Bring noodles to a boil.
Dice spinach or squeeze liquid out of canned spinach. Preheat oven to 400. Spray glass dish with cooking spray.
Combine spinach, ricotta, fontina, parmesan, egg, salt and pepper. Mix well.
Stuff cooked shells with the cheese mixture and set into baking dish.
Top with marinara sauce and more parmesan.
Cook for 30 minutes.