01 - Boil pasta in salted water until al dente, drain and retain ½ cup of pasta water.
02 - Heat olive oil in a skillet over medium heat; cook onion until translucent, then add garlic and sauté for 1 minute.
03 - Add crushed tomatoes, sugar, salt, black pepper, and red pepper flakes; simmer for 8 to 10 minutes stirring occasionally.
04 - Reduce heat, stir in heavy cream, and let simmer for 2 to 3 minutes until slightly thickened.
05 - Add drained pasta to sauce; toss well, adding reserved pasta water as needed for desired creaminess.
06 - Remove from heat and fold in torn basil and grated Parmesan; adjust seasoning to taste.
07 - Plate immediately, garnishing with extra Parmesan and basil if desired.