Bring a pot of lightly salted water to a boil. Add rotini and cook 8 to 10 minutes. Drain, place in a bowl with 1 tablespoon olive oil and set aside.
Meanwhile, toast walnuts in a large sauté pan over medium heat, about 5 minutes. Shake pan about halfway through cooking time. Set aside.
Heat remaining 2 tablespoons of olive oil in the same pan on medium-high. Add zucchini, summer squash, black pepper and 1/4 teaspoon salt and cook 5 minutes until slightly tender but still crisp; stir frequently. Add garbanzo beans and walnuts and heat through, about 2 minutes.
Add vegetable mixture to drained pasta with remaining 1/4 teaspoon salt, mint and 1/2 cup of Parmesan. Stir to combine, then top with remaining Parmesan.