Cook the Pasta
Bring a large pot of salted water to a boil. Cook pasta until al dente. Reserve ½ cup pasta water, then drain.
Sauté the Garlic
Heat olive oil or butter in a skillet over medium heat. Add garlic and cook until fragrant, about 30 seconds.
Simmer the Tomatoes
Stir in crushed tomatoes, salt, pepper, chili flakes, and sugar if using. Simmer gently for 10 minutes.
Add the Cream
Reduce heat to low and slowly stir in the cream until the sauce becomes smooth and velvety.
Combine with Pasta
Add cooked pasta to the sauce. Toss gently, adding reserved pasta water as needed to loosen the sauce.
Serve
Taste and adjust seasoning. Serve warm with Parmesan and fresh herbs if desired.