Cut the tops off the bell peppers and remove the seeds and membranes. Arrange the peppers upright in a baking dish.
In a large mixing bowl, combine the shredded chicken, buffalo sauce, cream cheese, half of the cheddar cheese, green onions, celery, garlic powder, salt, and pepper. Stir until well mixed.
Carefully spoon the buffalo chicken mixture into each prepared bell pepper until they are packed and overflowing slightly.
Sprinkle the remaining cheddar cheese on top of each stuffed pepper.
Cover the baking dish with foil and bake in the preheated oven for 30 minutes.
After 30 minutes, remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden brown.
Once out of the oven, let the peppers cool for a few minutes before serving. If desired, sprinkle with blue cheese crumbles for an extra kick.
Notes
Optional blue cheese crumbles can be added for extra flavor.