Mamma Agata's basic tomato sauce is the base for this recipe. If you have already made the sauce, bring it to simmer in a saucepan. Otherwise, prepare the sauce according to the directions here, then proceed as follows.
Add the vodka to the simmering sauce, and stir to incorporate. You should notice a shimmering effect on the surface of the sauce. Allow to simmer for about 2 minutes, or until you no longer smell alcohol vapors when you stir the sauce. Add the cream and butter, then stir to combine. Add the cheese and red pepper flakes, then keep warm until ready to use.
To finish, bring a large pot of salted water to a boil. Cook the penne one minute less than the package instructions indicate. Drain the pasta reserving about ¼ cup of pasta water.
Return the pasta to the large pot, add the vodka sauce, and stir to combine. Add a splash of pasta water and simmer for a minute or two, just until the sauce thickens slightly. Serve immediately.
Recipe by The Taste Edit at https://thetasteedit.com/how-to-make-penne-alla-vodka/