Boil the pasta until almost al dente (generally for the time indicated on the package minus 30-60 seconds). Reserve one cup of the pasta water, drain the pasta, and set it aside.

In the same pot, over medium heat, melt the butter and add the chili flakes, lemon zest, and minced garlic. Sauté them for about 30 seconds, stirring.

Add the lemon juice and zest from one lemon and mix it all in. Then add the pasta, stirring well so it absorbs the lemon juice and butter along with the spices.

Add parmesan a bit at a time and pasta water a bit at a time, alternating while mixing everything so the sauce emulsifies. You may use anywhere from 1/2 cup to 1 cup of pasta water, depending on how the sauce emulsifies.

Taste and add more lemon juice as needed. I prefer it with the juice from two large lemons, but my family prefers it with the juice of one. So adjust to your taste. You can also add freshly ground black pepper, flaky sea salt, more chili flakes, and parmesan to taste.

Add the finely chopped fresh basil, stirring everything in. Serve and enjoy!