Bring a large pot of salted water to boil and cook the pasta until al dente-- firm but tender.
Place the tomatoes in a bowl and squish them with your fingers to break them down. Set aside.
Blend the cashews with 1/2 cup of water until very smooth. Set aside.
While the pasta water is boiling, heat the oil in a large saucepan. Add the onions, season with some salt and pepper, and cook until the onion is softened, about 5 minutes.
Stir in the garlic and cook another minute. Add the tomatoes, vodka, oregano and red pepper flakes. (Anytime you add alcohol to a pot that's on the stove, make sure you either turn the heat off or very low).
Stir, bring the sauce to a boil, then turn down the heat and let it continue to simmer for 10 minutes.
Stir in the cashew cream and let it all warm through. Turn off the heat. Drain the cooked pasta and add it the sauce and mix well. Check for salt and pepper and add more if needed. Garnish, if you wish, with fresh parsley or oregano. Serve hot.