Bring water to boil. Add pasta and 1 teaspoon salt; cook, stirring frequently, until al dente. Drain pasta into colander set in bowl, reserving cooking water. Save 1 1/2 cup of cooking water; return pasta to now-empty bowl.
Slowly whisk 1 cup cooking water into 4 oz finely grated Romano 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.