In an unheated skillet large enough to hold the pasta later, combine the oil, garlic, crushed red pepper and 1 teaspoon of salt, stirring to coat with the oil.  Cook over low-moderate heat for 2-3 minutes.  Do NOT brown garlic.  Add crushed tomatoes.  Stir to blend, and simmer uncovered until the sauce thickens about 15 minutes.  (This step is super important.  The sauce needs to thicken for the flavors to intensify.  So the amount of time you cook it is less important than the consistency.  You may need to cook it longer than 15 minutes.)   Taste for seasoning.

Meanwhile, bring 6 quarts of water to a rolling boil.  Add 2-3 tablespoons of salt and the penne.  Stir to prevent sticking and cook until al dente.  Drain thoroughly.

Add the drained pasta to skillet with the tomato sauce. Toss. Add the vodka, and toss again, then add the cream and toss.  Cover, reduce the heat to low and let rest for 1 to 2 minutes to allow the pasta to absorb the sauce.  Sprinkle with parsley and serve.