In a large saucepan or Dutch oven, heat the oil over medium heat. Add the onions and cook, stirring frequently, until the onions become translucent, about 4 -5 minutes. Stir in the garlic, oregano, and pepper flakes and cook for just a minute. Season lightly with salt and ground black pepper.
1 small yellow onion, 2 garlic cloves, ½ teaspoon dried oregano, ¼ teaspoon red pepper flakes
Add the vodka and simmer for about 3-4 minutes or until the mixture is reduced by half.
½ cup vodka
Add the tomato paste and the whole tomatoes and their liquid into the pot. Bring to a simmer and cook stirring often while crushing the tomatoes roughly with a wooden spoon, until the sauce has thickened, about 8-10 minutes.
1 tablespoon tomato paste, 1 (28-ounces) can San Marzano whole plum tomatoes
Stir in the heavy cream and mix to combine.
Transfer the sauce to a blender or a food processor fitted with a steel blade and puree until smooth.
Meanwhile, cook the pasta in salted water according to package directions, until al dente. Reserve about 1 cup of the pasta water then, drain the pasta and set aside.
12 ounces tubed pasta like penne or rigatoni
Return the sauce to the pot and simmer over low heat, partially covered for about 6-8 minutes. Season to taste.
Add the pasta to the sauce and about ¼ cup of the reserved pasta water. Cook stirring constantly for about 2 minutes or until the pasta is well coated with the sauce. If the sauce thickens too much, add additional pasta water.
Remove from the heat and stir the Parmesan cheese. Serve immediately sprinkled with extra Parmesan cheese and garnished with fresh basil or parsley (if desired).
½ cup freshly grated Parmesan cheese