Cook 2 minced shallots in a skillet with butter over medium heat until slightly softened, 3 minutes. Add 1 minced garlic clove and a pinch of red pepper flakes; cook 30 seconds. Remove from the heat. Add 1/2 cup vodka, a 28-ounce can crushed tomatoes and some salt. Simmer, stirring, 7 minutes. Stir in 2/3 cup heavy cream and simmer until thickened, 3 minutes. Stir in 1/2 cup grated parmesan and a handful of torn basil. Toss with 12 ounces cooked penne, adding some pasta-cooking water to loosen.