Bring a large pot of water to a boil. Generously season with coarse sea salt. Cook rigatoni according to the package instructions until slightly softened but still firm, about 8 - 10 minutes.
Meanwhile, as the pasta is cooking, add olive oil and onion to a saute pan. Turn heat to medium and cook until translucent, about 5 minutes. Add garlic and cook just until fragrant, about 1 minute. Add tomato paste and Calabrian chili paste and cook until the mixture darkens.
Remove the saute pan from the heat (to avoid the vodka from flaming), add vodka, and scrape off any browned bits on the bottom of the pan. Add a ladle (about ¼ cup or 60 ml) of pasta water to loosen the sauce.
Transfer the cooked pasta over to the saute pan (reserve the pasta water). Turn heat to high and saute the pasta while vigorously stirring with a wooden spoon. Add a ladle (about ¼ cup or 60 ml) of pasta water (pour along the outside of the saute pan not directly on the pasta) and continue vigorously stirring. Repeat this process two to three additional times, adding more pasta water when you hear sizzling until a creamy sauce forms and the pasta is al dente.
Turn off the heat and add heavy cream. Toss pasta with parmesan. Taste and season as needed with salt and pepper.
Serve immediately. Optionally garnish with additional parmesan.