Preheat oven to 375°F and spray a 9x13-inch baking dish with cooking spray.
In the prepared baking dish, combine the chickpeas, frozen broccoli, cheddar cheese soup, sour cream, 1 cup of shredded cheddar cheese, minced garlic, onion powder, salt, and black pepper, stirring until everything is well mixed.
Spread the mixture evenly in the dish and top with the remaining 1 cup of shredded cheddar cheese.
In a small bowl, combine the panko breadcrumbs with the melted butter, then sprinkle evenly over the cheese layer.
Bake uncovered for 30-35 minutes until the casserole is hot and bubbly and the breadcrumb topping is golden brown.
Let cool for 5 minutes before serving.