Fill a large pot with salted water and bring it to a rolling boil. Add 2 cups of rigatoni and cook according to the package instructions until al dente, usually around 10-12 minutes. Stir occasionally to prevent sticking. Once cooked, reserve about 1/2 cup of pasta water, then drain the rigatoni and set aside.
While the pasta cooks, heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the finely chopped onion and sauté for about 3-4 minutes until translucent and fragrant. Add the minced garlic and cook for an additional 1 minute, stirring constantly to avoid burning.
Pour in the can of crushed tomatoes, stirring well to combine with the onions and garlic. Sprinkle in 1/2 teaspoon of red pepper flakes, salt, and pepper to taste. Let the sauce simmer gently for 5 minutes, allowing the flavors to meld beautifully.
Lower the heat and stir in 1/2 cup of heavy cream, blending it smoothly into the tomato sauce. If using, pour in about 1/4 cup of vodka and stir well. Let it simmer for another 2-3 minutes to marry all the ingredients.
Add the drained rigatoni directly into the skillet with the sauce. Toss gently to coat each pasta piece in the creamy tomato goodness. If the sauce feels too thick, add a splash of the reserved pasta water to loosen it up and create a silky texture.
Remove the skillet from heat. Tear fresh basil leaves and sprinkle them generously over the pasta. Serve immediately with a generous shower of grated parmesan cheese on top.