Bring a large pot of salted water to a boil and cook the farfalle pasta according to package instructions until al dente, about 10-12 minutes. Reserve 1/2 cup of the pasta water, then drain the rest.

In a skillet, heat olive oil over medium heat. Add onion and sauté for 3-5 minutes until translucent. Stir in minced garlic and red pepper flakes for an additional minute.

Pour crushed tomatoes into the skillet and bring to a gentle simmer. Cover and cook for 8-10 minutes, stirring occasionally.

Reduce heat to low and whisk in heavy cream. Gradually add reserved pasta water, stirring continuously to achieve desired creaminess.

Add drained farfalle to the sauce and toss gently to coat. Stir in grated Parmesan and chopped basil until melted and combined.

Taste and adjust seasoning with salt and black pepper. Serve immediately, garnished with extra Parmesan and basil.