1. Place finely grated Pecorino in medium bowl. Set colander in large bowl.
2. Bring 2 quarts water to boil in large Dutch oven. Add pasta and 1½ teaspoons salt; cook, stirring frequently, until al dente. Drain pasta into colander set in bowl, reserving cooking water. Pour 1½ cups cooking water into liquid measuring cup and discard remainder; return pasta to now-empty bowl.
3. Slowly whisk 1 cup reserved pasta cooking water into finely grated Pecorino until smooth. Whisk in cream, oil, and black pepper. Gradually pour cheese mixture over pasta, tossing to coat. Let pasta rest 1 to 2 minutes, tossing frequently, adjusting consistency with remaining ½ cup reserved pasta water. Serve, passing coarsely grated Pecorino separately.