Bring a large saucepan of water to a boil. Add the salt.
While the water is coming to a boil, melt the butter in a large skillet over medium heat. Add the freshly cracked black pepper and cook for 30 seconds. Remove from the heat and set aside.
Cook pasta until al dente (typically the lower end of package recommended cook times).
Use tongs to transfer the pasta to the butter in the skillet. It's ok if some pasta water gets in there — it'll help create a sauce. Add both cheeses and toss the pasta with the tongs until coated. If the pasta seems dry, add a ladle of pasta water and continue to toss with the tongs until the pasta is coated.
Transfer the pasta to a serving dish and garnish with additional freshly cracked black pepper and cheese, if desired.