1. Bring a large pot of salted water to a boil. Add the penne and cook until al dente, about 10-12 minutes. Drain and set aside.
2. In a large skillet, heat the olive oil over medium heat. Add the minced garlic and chopped onion, sautéing until the onion becomes translucent, about 3-4 minutes.
3. Stir in the crushed tomatoes and bring to a gentle simmer. Let it cook for about 8 minutes, allowing the flavors to meld.
4. Reduce the heat to low and slowly stir in the heavy cream, ensuring the sauce is smooth and creamy. Add the red pepper flakes, salt, and pepper to taste.
5. Add the cooked penne to the skillet, tossing it gently to coat the pasta with the sauce. Stir in the fresh basil and half of the Parmesan cheese.
6. Serve the pasta hot, garnished with the remaining Parmesan cheese and fresh parsley if desired.

As you cook, remember that pasta is forgiving. If your sauce appears too thick, a splash of pasta water can bring it to the perfect consistency. This was a trick Nonna Rosa swore by, and it never fails to deliver.