Cook the Pasta: Bring a large pot of generously salted water to a rolling boil. Add the spaghetti and cook according to package instructions until al dente, maintaining a slight firmness to the bite. In the final 2-3 minutes of cooking, carefully reserve 1 cup of the starchy pasta cooking water in a heatproof measuring cup—this liquid gold will help create your silky sauce.

Create the Aromatic Base: About 3-4 minutes before your pasta is ready, melt the butter in a large skillet over medium heat, swirling the pan as it melts. Allow the butter to foam gently, then reduce the heat to low. Add the lemon zest and minced garlic to the fragrant butter, stirring constantly for 1 to 2 minutes until the garlic becomes aromatic and golden but not browned. Watch carefully to prevent burning—the low heat is key here.

Combine and Emulsify: When the pasta reaches al dente perfection, use tongs to transfer it directly from the pot to the skillet with the butter mixture (this method brings some pasta water along naturally). Add ½ cup of the reserved pasta water and toss vigorously over low heat until a light, glossy sauce begins to form around the pasta. Sprinkle in half of the Parmesan cheese and toss again until melted and incorporated. Pour in the lemon juice and add the remaining cheese, continuing to toss until the sauce becomes smooth and creamy. If the sauce becomes too thick or starts to clump, gradually add more pasta water, one tablespoon at a time, until you achieve a silky consistency that coats each strand perfectly.

Finish & Serve: Season the pasta to taste with sea salt, freshly cracked black pepper, and an extra squeeze of lemon juice if desired for more brightness. Transfer to serving plates or a large pasta bowl. Garnish generously with additional lemon zest for aromatic oils, freshly chopped parsley or basil for a pop of color, and extra Parmesan cheese. Serve immediately while hot and creamy, with additional cheese at the table.