Boil water with salt, zest and juice lemons, mince garlic, grate cheese, tear basil leaves.
Cook spaghetti until al dente, reserve 1 cup pasta water, drain without rinsing.
Heat olive oil, sauté garlic, add lemon juice + zest, whisk parmesan + pasta water until smooth.
Add spaghetti to skillet, toss with sauce, add more pasta water as needed, season to taste.
Garnish with basil and extra parmesan, serve hot.