Combine panko bread crumbs, Italian-seasoned bread crumbs, garlic powder, salt, and pepper in a bowl. Pour Buffalo wing sauce into a separate bowl.
Coat chicken breast pieces on both sides with the Buffalo sauce then evenly coat with bread crumb mixture. Lay pieces flat on a baking sheet.
Bake in the preheated oven until no longer pink in the center, juices run clear, and chicken has reached desired crispiness, about 20 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).