In a large bowl, whisk oil, cheese, lemon juice, salt and pepper to blend.
In a large deep pot, boil some water with salt.
Add Spaghetti to the pot and cook, stirring occasionally, until tender. It should take about 8 to 10 mins.
Drain the Spaghetti once it is cooked and save the pasta water. You can add this later to moisten the Spaghetti.
Add the Spaghetti to the lemon sauce. Then, add chopped cilantro and lemon zest.
If it's too dry, you can add some pasta water.
Garnish with some more grated Parmesan cheese and serve hot.