Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions until al dente.
While the pasta is cooking, in a large skillet or saucepan, toast the freshly ground black pepper over medium heat for about 1-2 minutes until fragrant. Be careful not to burn it.
Once the pasta is cooked, reserve about 1 cup of pasta cooking water, then drain the pasta and set aside.
In the same skillet or saucepan with the toasted black pepper, add about 3/4 cup of the reserved pasta cooking water. Bring it to a simmer.
Gradually add the finely grated Pecorino Romano cheese to the simmering water, whisking constantly until it forms a smooth and creamy sauce. Add more pasta cooking water as needed to achieve the desired consistency.
Add the cooked pasta to the sauce in the skillet or saucepan. Toss well to coat the pasta evenly with the cheese and pepper sauce.
Taste and adjust the seasoning with salt if necessary. Remember that Pecorino Romano cheese is naturally salty, so be cautious with additional salt.
Serve the Cacio e Pepe immediately, garnished with extra Pecorino Romano cheese and freshly chopped parsley if desired.