The bones of this recipe come from Saveur, because it is the simplest, purest version I've found yet. Feel free to go off the hip on cheese and butter amounts—most of this dish can just be cooked to taste. You can even—gasp—use another type of pasta if you wish. —Kenzi Wilbur
Bring cream to a scant boil in a high-sided skillet or pot. Turn town to a simmer, and reduce by about half.
Cook pasta to al dente in a large pot of salted water, then drain and add to the reduced cream. Add cheese, butter, and black pepper to taste. Toss until everything is well-combined. Serve with parsley if you wish.