In a large pot, bring salted water to a boil and cook spaghettoni according to package instructions until al dente.
Reserve about ½ cup of pasta cooking water before draining.
In the same pot, add ricotta cheese, lemon zest, lemon juice, and olive oil.
Slowly add reserved pasta water while stirring to create a smooth, creamy sauce.
Return the cooked pasta to the pot and toss gently until evenly coated.
Season with salt and black pepper to taste.
Garnish with grated parmesan and fresh herbs if desired, then serve immediately.