Start by bringing a large pot of salted water to a boil. Add the rigatoni and cook according to the package instructions until al dente. Reserve about 1 cup of pasta water, then drain the pasta in a colander.
While the pasta is cooking, heat the extra virgin olive oil in a large skillet over medium heat. Add the smashed garlic cloves and crushed red pepper flakes. Sauté for about 1-2 minutes until the garlic is fragrant but not browned.
Add the chopped kale to the skillet with the garlic and olive oil. Toss to coat the kale with the oil and cook for about 5-7 minutes, stirring occasionally, until the kale is wilted and tender.
Once the kale is cooked, add the drained rigatoni to the skillet. Toss everything together, adding a splash of the reserved pasta water to help combine the sauce with the pasta. Stir in the lemon zest and lemon juice, mixing until well combined.
Remove the skillet from heat and stir in the freshly grated Parmesan cheese. Taste and adjust seasoning with more lemon juice, salt, and freshly ground black pepper as desired. Serve hot, garnished with extra Parmesan and a sprinkle of black pepper.
