Bring a large pot of salted water to a boil.
Add pasta and cook until al dente, following package directions for timing.
While pasta cooks, melt butter in a large skillet over medium-low heat.
Add minced garlic to the butter and cook for 1 minute until fragrant, stirring frequently.
Zest both lemons directly into the skillet, then squeeze the lemon juice into a measuring cup—you should have about ½ cup.
Pour the lemon juice into the skillet with the butter and garlic mixture, stirring gently to combine.
Reserve 1 cup of pasta water before draining the cooked pasta.
Transfer the drained pasta to the skillet with the lemon sauce.
Toss everything together, adding pasta water gradually until the sauce coats the pasta evenly and becomes silky.
Remove the skillet from heat.
Stir in half of the Parmesan cheese.
Season with sea salt and freshly cracked black pepper to taste.
Divide among serving bowls and top with remaining Parmesan cheese and fresh parsley.
Serve immediately while hot.