Preheat oven to 350°F. Line a 9x13 pan with Reynolds Wrap® Heavy Duty Foil.
Place lasagna noodles in a pan and cover with boiling water for 15 minutes. Rinse with cold water and dab dry.
Meanwhile, heat olive oil over medium heat in a large skillet. Add onion and garlic and cook until tender, about 5 minutes. Add pasta sauce and Italian seasoning. Simmer 5 minutes more or until slightly thickened.
While sauce is simmering, squeeze spinach to remove moisture. Combine with ricotta cheese, 2 ½ cups mozzarella cheese, ¼ cup parmesan cheese, egg, and fresh parsley. Mix well.
Place 1 cup of sauce in the bottom of the prepared pan.
Layer with 3 lasagna noodles. Add ½ of the spinach and cheese mixture and ⅓ of the sauce.
Add 3 more lasagna noodles, remaining ½ of the spinach and cheese mixture, and ⅓ of the sauce. Top with the last 3 noodles and the remaining sauce.
Cover with Reynolds Wrap® Heavy Duty Foil to ensure it is well sealed and bake 45 minutes. Remove foil, top with remaining mozzarella and parmesan cheese. Bake an additional 15-20 minutes or until browned.
Cool 20 minutes before cutting.