Begin by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add your spaghetti and cook according to package instructions until it's al dente, typically about 8-10 minutes. Toward the end of cooking, reserve 1 cup of the starchy pasta water, then drain the spaghetti and set it aside.

In a large skillet, melt 4 tablespoons of unsalted butter over medium heat until foamy, about 1-2 minutes. Keep an eye on it to prevent burning.

Once the butter is foamy, reduce the heat to low and add the zest of one lemon with 2 minced garlic cloves. Stir continuously for 1-2 minutes until fragrant.

Using tongs, transfer the drained spaghetti directly into the skillet with the butter mixture. Pour in about ½ cup of the reserved pasta water and toss the spaghetti to evenly coat it in the buttery sauce.

Stir in half of the grated Parmesan cheese and the juice of one lemon, tossing until everything combines smoothly. Add more pasta water if the sauce is too thick.

Taste and add sea salt and black pepper as needed. Garnish with additional lemon zest and fresh parsley or basil before serving.