Start by bringing a large pot of salted water to a rapid boil over high heat. Once boiling, add the rigatoni and cook according to the package instructions until al dente, usually around 8-10 minutes. Before draining, reserve about 1 cup of the pasta water, then drain the pasta and set aside.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the minced garlic and sauté for about 1 minute, stirring frequently until fragrant and light golden. Do not let it brown.

Toss in a handful of fresh spinach or arugula and sauté for approximately 2-3 minutes until wilted.

Reduce heat to low and add the ricotta cheese, lemon zest, and lemon juice. Stir gently to combine into a smooth sauce.

Add the drained pasta to the skillet, tossing it in the creamy sauce. Adjust the sauce's thickness with reserved pasta water if necessary.

Stir in grated Parmesan cheese, salt, pepper, and optional red pepper flakes. Adjust seasoning to taste.

Serve immediately, garnished with additional lemon zest and black pepper. Enjoy with a side salad or garlic bread.