01 - Preheat the oven to 375°F. Grease a 9-inch springform pan with olive oil and line the base with parchment paper.
02 - Boil rigatoni in a large pot of salted water until very al dente, about 2 minutes less than package directions. Drain and toss with 1 tablespoon olive oil. Set aside.
03 - Heat olive oil in a saucepan over medium. Sauté onion until translucent, about 3–4 minutes. Add garlic and sauté 1 minute more. Stir in crushed tomatoes, tomato paste, oregano, basil, sugar, salt, and pepper. Simmer for 15–20 minutes, stirring occasionally. Adjust seasoning as needed.
04 - In a bowl, combine ricotta, 1 cup mozzarella, Parmesan, egg, parsley, salt, and pepper. Stir until smooth.
05 - Stand rigatoni noodles upright, tightly packed, in the prepared pan. Use a piping bag or small spoon to fill each tube with the cheese mixture.
06 - Spread tomato sauce evenly over the filled pasta, letting it seep between noodles. Sprinkle the remaining mozzarella cheese on top.
07 - Cover pan loosely with foil and bake for 30 minutes. Remove foil and bake for an additional 15 minutes until the cheese is golden and bubbling.
08 - Cool for 10 minutes before releasing the pan. Garnish with extra parsley and Parmesan. Slice and serve.