Boil the pasta until al dente according to package instructions, drain and keep warm.
In a large sauce pan on medium heat, add oil, onion and garlic and cook 5 minutes until softened.
Add the tomatoes, oregano, red pepper flakes and vodka being careful not to flame the vodka.
Stir and simmer about 20 minutes until the sauce has reduced about 25%.
Remove from the heat and use an immersion blender to puree the sauce, (you can also use a blender or a food processor).
Put the pot back on medium heat and stir in the cream and parmesan cheese.
Taste the sauce and add salt and pepper as you see fit.
While still on the heat, add the shrimp and let them cook for 2 or 3 minutes until nearly opaque.
Remove the sauce from the heat and let the shrimp finish for another minute, then add the cooked pasta.
Stir together and serve hot with extra parmesan cheese.