Bring a large pot of water to a boil.
Add the cavatappi and cook to al dente. Reserve 1 cup of pasta water prior to straining.
Add the strained pasta back to the pot over medium-low heat along with the butter and pepper, stirring to melt the butter.
Add ½ cup of the pasta water, stirring to incorporate it into the pasta.
Stir in the cheese to create a sauce. Add an additional ¼ cup of pasta water, 1 to 2 tablespoons at a time, as needed, to thin the sauce to preference.
Season with salt, to taste. Serve immediately topped with additional grated Pecorino Romano cheese. Enjoy!