03Meanwhile, combine the ricotta, 1 1/2 to 2 cups mozzarella cheese, 1/2 cup Parmesan, and parsley. Add the garlic, salt, and pepper to taste, and mix. Stir the cooled meat mixture into the cheese mixture.04Preheat the oven to 350 degrees F.05Brush the remaining 2 teaspoons of oil over a 13 by 9 by 2-inch glass baking dish. Spoon 1 1/2 cups of the marinara sauce over the bottom of the prepared dish. Fill the manicotti with the cheese-meat mixture. Arrange the stuffed pasta in a single layer in the prepared dish and spoon the remaining sauce over.06Sprinkle the remaining 1 1/2 cups of mozzarella cheese, then the remaining 1/2 cup of Parmesan over the stuffed pasta. Dot entire dish with the butter pieces. Bake the manicotti uncovered until heated through and the sauce bubbles on the sides of the dish, about 30 to 35 minutes. Let the manicotti stand 5 minutes and serve.