Bring a large pot of salted water to a boil. Add the rigatoni to the boiling water and cook just until al dente. Drain, but reserve 1 cup of pasta cooking liquid.
Meanwhile, warm olive oil in a large, heavy bottomed pot over medium heat. Add pancetta and cook, stirring occasionally until crispy (4 to 5 minutes). Stir in onion, garlic and red pepper flakes, and cook, stirring occasionally until the onion is translucent (about 4 minutes).
Add tomato paste and cook, stirring often, until it takes on a deeper shade of red and starts to brown on the bottom of the pot (6 to 7 minutes). Deglaze the pan with the vodka, scraping up any bits that may be stuck on the bottom of the pot. Reduce heat to low, then slowly stir in the heavy cream to form a smooth sauce. Season to taste with salt and black pepper.
Add the cooked rigatoni to the pot along with 1/2 cup of hot cooking liquid. Gradually add the Parmesan cheese, stirring constantly to melt the cheese. Splash in pasta cooking liquid as needed if the sauce is too thick. The sauce should evenly coat the rigatoni, but you don’t want to see liquid pooling at the bottom. Check for seasoning one last time. You may need to add more salt.
To serve, spoon rigatoni into a shallow bowl, then top with a sprinkling of Parmesan cheese and a few basil leaves.