01 - Bring a large pot of salted water to a rolling boil. Add pasta and cook until al dente according to package directions. Reserve 1/2 cup of the starchy pasta water before draining thoroughly.
02 - While pasta cooks, warm olive oil in a large skillet over medium heat. Add the chopped onion and cook for 3-4 minutes until translucent and softened, stirring occasionally.
03 - Stir in the minced garlic and cook for just 1 minute until fragrant, being careful not to brown or burn it.
04 - Add tomato paste to the skillet and cook for 1 minute, stirring constantly to deepen its flavor and caramelize slightly.
05 - Pour in the crushed tomatoes, then add sugar, dried oregano, and red pepper flakes if desired. Season generously with salt and pepper. Let the sauce simmer uncovered for 8-10 minutes, stirring occasionally until slightly thickened.
06 - Reduce heat to low setting. Pour in the heavy cream and sprinkle in the Parmesan cheese. Stir continuously for 2 minutes as the cheese melts and the sauce transforms into a velvety consistency.
07 - Transfer the drained pasta directly into the sauce. Add reserved pasta water a little at a time until the sauce clings beautifully to the pasta. Toss thoroughly to coat every piece. Serve immediately topped with torn fresh basil and additional grated Parmesan.