01 - Bring a large pot of salted water to a boil. Cook pasta according to package instructions until al dente. Reserve ½ cup of pasta water and drain the pasta.
02 - Heat olive oil in a large skillet over medium heat. Sauté the finely chopped onion for 3-4 minutes until translucent. Add minced garlic and cook for 1 minute until fragrant.
03 - Add crushed tomatoes, tomato paste, sugar, dried oregano, chili flakes if using, salt, and black pepper. Simmer the mixture for 10 minutes, stirring occasionally.
04 - Reduce heat to low. Stir in heavy cream and grated Parmesan cheese. Simmer for 2-3 minutes until the sauce thickens and becomes creamy.
05 - Add the drained pasta to the sauce, tossing gently to coat evenly. If necessary, add reserved pasta water a little at a time to achieve the desired consistency.
06 - Plate the pasta immediately. Garnish with fresh basil leaves and additional Parmesan if desired.