01 -  Preheat oven to 375°F. Grease a 9-inch springform pan with olive oil and line base with parchment paper. 
 02 -  Boil rigatoni in a large pot of salted water until very al dente, approximately 2 minutes less than package instructions. Drain and toss with 1 tablespoon olive oil. 
 03 -  Warm 2 tablespoons olive oil in a saucepan over medium heat. Sauté onion until translucent, around 3–4 minutes. Add garlic and cook 1 minute. Incorporate crushed tomatoes, tomato paste, oregano, basil, sugar, salt, and pepper. Simmer for 15–20 minutes, stirring occasionally and adjusting seasoning to taste. 
 04 -  Combine ricotta, 1 cup mozzarella, Parmesan, egg, parsley, salt, and pepper in a medium bowl. Stir until smooth. 
 05 -  Pack rigatoni upright and tightly into the prepared pan. Fill each pasta tube with cheese mixture using a piping bag or spoon. 
 06 -  Pour prepared tomato sauce evenly over pasta, letting it seep between the noodles. Top with remaining 1 cup mozzarella. 
 07 -  Cover pan loosely with foil and bake for 30 minutes. Remove foil and bake an additional 15 minutes until the cheese is golden and bubbling. 
 08 -  Allow dish to rest 10 minutes before releasing springform ring. Garnish with extra parsley and Parmesan, slice, and serve.