For the garnish: chopped parsley, red pepper flakes (optional)
Instructions
Bring a large pot of well-salted water to a boil. Cook the pasta until it is al dente, testing a few minutes before the package instructions indicate. Using a glass liquid measuring cup, reserve 1/2 cup of the hot pasta water, then drain the pasta.
In a saucepan, mix the ricotta, olive oil, Parmesan cheese, kosher salt, black pepper, lemon zest, and 1/4 cup pasta water. Warm over medium heat and stir until a creamy sauce forms, about 1 minute.
Pour the sauce onto the noodles and stir to combine. Add another splash of pasta water to help the sauce coat the noodles. Serve with chopped parsley, additional grated Parmesan cheese and the reserved lemon zest. (Leftovers last 2 days refrigerated but the sauce becomes thick when cold. Reheat with a splash of milk and additional kosher salt to revive the flavors.)