Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente. Reserve 1 cup of pasta water, then drain the pasta in a colander.
In the same pot, heat 1 tablespoon of olive oil over medium heat. Add minced garlic and sauté for about 1 minute until fragrant, but not browned.
Add the chopped spinach to the pot and cook, stirring frequently, until wilted, about 2-3 minutes.
In a mixing bowl, combine ricotta cheese, lemon zest, lemon juice, salt, pepper, and grated Parmesan cheese. Mix well until smooth.
Return the cooked pasta to the pot with the spinach and garlic. Reduce the heat to low, and add the ricotta mixture. Stir gently to combine, adding reserved pasta water as needed to reach your desired creaminess.
Taste and adjust seasoning with salt and black pepper, if necessary.
Serve immediately, garnished with additional Parmesan cheese and fresh herbs, if desired.