Cook the pasta in salted water. The water should taste as salty as sea water. You're going to cook the pasta 2 minutes less than the package directs. Using a ladle, carefully dip 1 cup of pasta water out, set aside. Drain the pasta.
While the pasta is cooking, melt the butter in a large skillet over low heat. Add the lemon zest. Allow the zest to cook gently in the butter for 2 or 3 minutes. Add the lemon juice and cook a couple of minutes more. Remove the skillet from the heat until the pasta is done.
Working very quickly, put the skillet back on the heat and immediately add the just-drained pasta to the lemony butter in the skillet. Add ½ cup of the hot pasta water, cheese, and several grinds of black pepper. Using tongs toss the pasta briskly over and over as the cheese melts. The sauce will emulsify and get creamy. The pasta will absorb most of it. Taste for seasoning and add more salt and pepper if needed. If the pasta looks a little dry, you can add a little more pasta water a tablespoon at a time.
Put hot pasta in a serving bowl and serve with more cheese, cracked black pepper, and lemon wedges.
