Bring a large pot of water to a boil and cook spaghetti according to package instructions.
Reserve 1/2 cup of pasta cooking water, then drain the spaghetti.
In a blender, combine spinach, basil, olive oil, lemon juice, garlic, and salt. Blend until smooth and vibrant green.
Return the cooked spaghetti to the pot and pour in the spinach sauce.
Toss well to coat, adding reserved pasta water gradually to reach your desired consistency.
Serve immediately and top with cheese, walnuts, pepper, and lemon zest.
This Creamy Lemon Spinach Pasta comes together quickly and delivers fresh flavor in every forkful.