in a large skillet, large enough to hold the pasta when cooked, sauté the garlic in the butter until it just begins to turn color, 2 to 3 minutes.
Add the cream and the zest and cook over medium heat, uncovered, 3 to 4 minutes, stirring most of the time with a rubber spatula. The cream should thickened a little. Add salt and freshly ground pepper.
Cook the pasta, drain it and add it to the sauce. Add one half of the lemon juice, toss the pasta lightly but well, cooking it 1 to 2 minutes over heat. Taste for lemon flavor and add more lemon juice if you feel it needs it. Top with parsley and serve. Makes four servings.