Cheesy Summer Squash Casserole

Preheat oven to 375°F. Coat an 8-inch square casserole dish with cooking spray.

Bring a large pot of water to a boil over high heat. Add squash, onion, bell pepper and poblanos; cook until the squash is just tender, about 6 minutes. Drain well. Transfer the mixture to a paper-towel-lined baking sheet; spread into a single layer and pat dry.

Stir together cheese, mayonnaise, pepper and salt in a large bowl; fold in the squash mixture. Transfer to the prepared casserole dish. Stir together panko and oil in a small bowl; sprinkle over the squash mixture.

Bake until bubbling and golden brown, about 25 minutes. Let stand for 5 minutes before serving.