Bring a large pot of salted water to a boil and cook rigatoni according to package directions until al dente.

While pasta cooks, heat olive oil in a large skillet over medium-high heat.

Add zucchini half-moons to the skillet and sauté for 5 to 7 minutes until tender and slightly browned.

Stir in minced garlic and red pepper flakes, cooking for 60 seconds until fragrant.

Reserve 1/2 cup of the starchy pasta water before draining the cooked rigatoni.

Transfer the drained pasta to the skillet with the zucchini mixture.

Add lemon juice, lemon zest, and half of the Parmesan cheese to the pan.

Toss vigorously, adding reserved pasta water 1 tablespoon at a time until a light sauce coats the pasta.

Season with salt and black pepper to taste.

Garnish with remaining Parmesan cheese and chopped fresh parsley before serving.