Grilled Whole Zucchini Pesto Pasta

Name: Grilled Whole Zucchini Pesto Pasta
Ingredients: 4 medium zucchini (about 1 1/2 pounds); 3 large ears of corn, shucked; 1 large shallot, halved lengthwise; 2 tablespoons olive oil; Kosher salt and freshly ground black pepper; 1 cup lightly packed fresh basil leaves, plus more torn basil leaves for serving; 1 cup lightly packed fresh parsley leaves; 1 pound cavatappi; 1/2 cup freshly grated Parmesan, plus more for serving; Finely grated zest and juice 1 large lemon; Crushed red pepper flakes, for serving, optional