Preheat oven to 350 degrees F.
Cook lasagna noodles according to package directions, then rinse in cold water and pat dry with paper towels.
In a large mixing bowl, combine spinach, ricotta, Parmesan, egg, salt and pepper until combined; set aside.
Spray a 9x13-inch baking pan with nonstick cooking spray.
Spread enough marinara sauce in the pan to cover the bottom in an even layer.
Divide cheese mixture equally between lasagna noodles and spread evenly over each noodle.
Roll up each noodle and place seam side down in prepared baking dish.
Spoon remaining marinara over rolled noodles and top with shredded mozzarella.
Cover with foil and bake for 40 minutes.
