Bring a large pot of water to boil. Add salt generously—the water should taste like seawater. Add pasta and cook according to package directions until just shy of al dente (about 1 minute less than package instructions).

While pasta cooks, toast the cracked peppercorns in a large skillet over medium heat for 1-2 minutes until fragrant. Remove from heat.

Reserve 2 cups of starchy pasta water before draining. Drain pasta but do not rinse.

Return the skillet with pepper to medium-low heat. Add 1 cup of hot pasta water to the pepper and bring to a gentle simmer.

Add the drained pasta to the skillet and toss vigorously for 1 minute, allowing the pasta to absorb some water and release starch.

Remove the pan from heat completely. Add butter (if using) and half the grated cheese. Toss rapidly with tongs, adding pasta water gradually until a creamy, glossy sauce forms that coats each strand.

Add remaining cheese gradually, tossing constantly. If the sauce looks too thick, add more pasta water 1 tablespoon at a time. If too thin, add more cheese.

Taste and adjust seasoning with additional pepper if desired. The sauce should be creamy and silky, not clumpy or broken.

Serve immediately in warmed bowls, topped with extra grated Pecorino Romano and freshly cracked black pepper.