Preheat the oven to 350. Lightly mist a baking sheet with cooking spray and set aside.
Fill a large pot with water and bring to a boil. Place the chicken breasts into the boiling water and boil, uncovered, for 15-30 minutes until cooked through. Remove chicken from the water and shred using two forks.
In a large bowl, combine the shredded chicken with the wing sauce, cheddar, blue cheese, scallions and cream cheese and stir together until thoroughly mixed. On a sheet of parchment paper or other flat, nonstick surface, separate the chicken mixture into 24 equal piles and then role each one into a ball.
In a shallow dish, combine the panko crumbs with salt and pepper and mix to combine. Roll each ball of chicken in the panko, coating the outside, and place it on the prepared baking sheet. Spray the tops of the panko-coated chicken bites with cooking spray and transfer them to the oven to bake for 20-25 minutes until panko is slightly browned and crunchy.