1 (15 ounce) container ricotta cheese
1 (10 ounce) package frozen chopped spinach, thawed and squeezed dry
1/2 cup minced onion
2 teaspoons minced fresh parsley
1/2 teaspoon pepper
1/4 teaspoon garlic powder
1 1/2 cups shredded mozzarella cheese, divided
1/2 cup grated Parmesan cheese, divided
2 (26 ounce) jars spaghetti sauce
1 1/2 cups water
1 (8 ounce) package manicotti shells
Preheat oven to 350 degrees F (175 degrees C).
In a large bowl, combine ricotta, spinach, onion and egg. Season with parsley, pepper and garlic powder. Mix in 1 cup mozzarella and 1/4 cup Parmesan. In a separate bowl, stir together spaghetti sauce and water.
Spread 1 cup sauce in the bottom of a 9×13 inch baking dish. Stuff uncooked manicotti shells with ricotta mixture, and arrange in a single layer in the dish. Cover with remaining sauce. Sprinkle with remaining mozzarella and Parmesan.
Bake in preheated oven for 45 to 55 minutes, or until noodles are soft.