In a large pot, bring salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Reserve 1 cup of pasta water, then drain the pasta and set aside.
In the same pot, heat the olive oil over medium heat. Add the minced garlic and chopped onion, sautéing for about 3-4 minutes until soft and fragrant.
Stir in the red pepper flakes for an extra kick, cooking for another minute.
Pour in the crushed tomatoes and bring the mixture to a gentle simmer. Let it cook for about 7-10 minutes until it thickens slightly and the flavors meld.
Lower the heat and stir in the heavy cream, mixing well until combined and the sauce turns a beautiful pink color. If the sauce is too thick, add some reserved pasta water until you reach the desired consistency.
Mix in the grated Parmesan cheese, stirring until it melts and the sauce is creamy. Season with salt and pepper to taste.
Add the cooked pasta to the sauce, tossing gently to coat the penne evenly in the spicy tomato sauce.
Plate the pasta and garnish with fresh basil leaves and extra Parmesan cheese on top.
Notes
For a dairy-free option, substitute heavy cream with coconut cream.