Bring a large pot of water to a boil and cook pasta according to package instructions until al dente.
While waiting for water to boil, whisk together the ricotta, lemon juice, 2 tablespoons olive oil, lemon zest, and seasoning to a small bowl.
While the pasta is boiling, heat a medium saucepan to medium heat. Add the remaining tablespoon of olive oil. Once glistening, add the garlic and sauté until fragrant for about one minute. Before your drain your pasta, scoop out at least a cup and a half of pasta water and reserve it for the sauce!
Add the lemon ricotta mixture to the sauce pan and allow it to heat up, whisking occasionally. Add about 1/2 cup of the reserved water water to thin the sauce out slightly and this will also help coat the pasta with the sauce. Go a touch thinner than you prefer as it will thicken slightly when you toss with the pasta and heat.
When pasta is ready, drain and add back to the pot along with spinach over top. Pour the lemon ricotta sauce over the pasta and spinach.
Toss the pasta with the sauce and allow it to coat evenly while also wilting the spinach. You can add more pasta water if it seems to thick. Adjust seasoning to taste and you are ready to serve!
Serve with freshly grated parmesan and chopped parsley or basil on top.