Cook penne according to directions on package. Drain and set aside. In a large skillet heat olive oil. Add garlic and cook for 30 seconds. Add vodka and cook until the flames dissipate. Add cream and bring to a boil. Reduce heat so that cream simmers. Stir until mixture has reduced in volume by half. Add tomato sauce and season with salt and pepper. Add cooked pasta. Stir until coated and heated through. Serve with grated Parmesan cheese.