Cook pasta until al dente according to package directions. We like this dish saucy so we usually use 8 oz of pasta. If you don't like it as saucy, feel free to use up to 1 lb. Reserve 1 cup of the starchy cooking water when the pasta is done.
In the meantime, heat olive oil or vegan butter in a large skillet over medium heat. Add red pepper flakes (if using) along with the diced onion and minced garlic. Sauté 3-5 minutes, until the onions are soft and translucent. We don't want to brown them.
Add in the tomato paste and stir to coat the onions and garlic. Keep cooking this mixture, stirring often, for about 5 minutes. We want to cook off the raw flavor of the tomato paste and slightly caramelize it. You'll know it's ready when it goes from a bright red color to a darker orange-red color.
Deglaze the pan with the vodka. Stir to combine, and to scrape off any tomato paste that might have started to stick to the pan. Cook for 2-3 minutes, allowing liquid to cook off until it has reduced by about half.
Stir in the cashew cream and vegan parmesan. Reduce the heat to medium-low if the sauce is bubbling vigorously.
Add in the al dente pasta along with 1/2 cup reserved pasta water and stir to coat. We will be finishing the cooking process for the pasta in the sauce, so keep cooking and stirring occasionally for another 2-3 minutes. The starch in the cooking water will thicken the sauce. If you feel it needs to be thinned out more, feel free to stir in additional pasta water a few tablespoons at a time, until you achieve the consistency you prefer.
Season with salt to taste.
Serve the pasta alla vodka with fresh chopped basil and, if you like, sprinkle on some extra vegan parmesan. Enjoy.