Zucchini spinach manicotti

Name: Zucchini spinach manicotti
Prep time: 20 min
Cook time: 25 min
Total time: 45 min
Cuisine: Italian, Mediterranean, European
Ingredients: 2 large zucchini; 1.5 cups part skim ricotta cheese; 1 egg; 1 cup frozen spinach, thawed and patted dry; 1.5 cups shredded reduced fat mozzarella cheese, divided; 1/4 cup grated parmesan cheese; 1/8 tsp salt; One cup tomato sauce