Preheat oven to 400°F. Lightly coat a 9-by-13-inch baking dish with cooking spray.
Bring a large saucepan of water to a boil. Add 8 ounces rotini; cook according to package directions. Drain.
Meanwhile, heat 2 tablespoons oil in a large skillet over medium heat. Add 1 cup onion; cook, stirring, until starting to soften, about 3 minutes. Add 3 cans tomatoes, 2 teaspoons garlic powder, 1 teaspoon oregano, ¾ teaspoon crushed red pepper, ½ teaspoon basil and ½ teaspoon salt; bring to a simmer. Cook, stirring, until warmed through, about 3 minutes. Stir in 2 cups chicken and the cooked rotini. Transfer to the prepared baking dish and top with 1 cup mozzarella.
Stir ½ cup panko, ¼ cup Parmesan, 2 tablespoons parsley and the remaining 2 tablespoons oil together in a small bowl. Sprinkle over the casserole. Bake until hot and the topping is golden, 25 to 30 minutes.
