Boil the Pasta Water: Cook spaghetti according to package directions. Be sure to salt the water.

Melt the Butter and Oil: While the water is heating, melt the butter and olive oil together in a large sauté pan over low heat.

Cook the Pasta: Once the water reaches a full boil, add the spaghetti and boil for 5 minutes — only halfway through the package directions. You’ll finish cooking it in the sauce.

Add Flavor to the Sauce: While the pasta cooks, add the minced garlic and half the lemon zest (about ½ tablespoon) to the melted butter mixture in the sauté pan. Stir frequently and keep it over low heat so the garlic doesn’t burn.

Transfer Pasta: After 5 minutes, use tongs or a spaghetti server to carefully lift the pasta straight from the boiling water into the sauté pan. Reserve the pasta water.

Add Lemon Juice and Pasta Water: Pour in the lemon juice and 1 cup of the reserved pasta water. Toss the pasta to coat it in the sauce.

Simmer and Toss: Cook for another 5 to 7 minutes, tossing frequently, until the spaghetti is fully cooked and silky. Add up to ½ cup more pasta water as needed to keep it saucy.

Add Cheese and Seasonings: Turn off the heat. Stir in the grated parmesan cheese, salt, and pepper until melted and fully incorporated.

Serve and Garnish: Plate the pasta and sprinkle with chopped parsley and the remaining lemon zest. Garnish with extra cheese, a drizzle of olive oil, salt, pepper, and a squeeze of fresh lemon, if desired.