Preheat the oven to 350°
Line a 9 x 13” baking dish with 2 cups of the tomato sauce.
In a large bowl, add the ricotta, 2 cups of the mozzarella cheese, Parmesan, egg, spinach, salt, pepper, garlic powder Italian Seasoning and oregano.
Mix everything together until it’s evenly combined. Using a spoon, fill the inside of the manicotti with the spinach and cheese filling.
Place them, side by side, into the baking dish.
Cover them in a little more sauce and sprinkle them with the rest of the mozzarella cheese.
Bake place them into the oven for about 20-30 minutes.
Let them cool slightly, garnish them with parsley (optional) and serve warm. Enjoy!