Bring a large pot of salted water to a rollling boil. Add rigatoni and cook for 8-10 minutes until al dente. Drain, reserving 1/2 cup of pasta water.

In a large skillet, heat olive oil over medium-high heat. Add zucchini and sauté for 5-7 minutes until tender.

Add minced garlic and red pepper flakes to the skillet. Cook for an additional minute until the garlic is fragrant.

Add drained rigatoni to the skillet. Drizzle with lemon juice and zest, then sprinkle with half of the Parmesan cheese. Toss well to coat.

Season with salt and black pepper to taste. Stir to combine all ingredients.

Transfer to bowls, garnish with remaining Parmesan and parsley, and drizzle with olive oil. Serve hot.