Preheat your oven to 375°F (190°C).
Prepare the bell peppers by cutting off the tops and removing the seeds.
In a mixing bowl, combine the shredded chicken, buffalo sauce, cream cheese, half of the cheddar cheese, green onions, garlic powder, salt, and pepper.
Spoon the buffalo chicken mixture into each bell pepper generously.
Place the stuffed peppers upright in a baking dish and drizzle with olive oil.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil, sprinkle the remaining cheddar cheese on top, and bake for an additional 10-15 minutes until the cheese is melted and bubbly.
Allow them to cool slightly before serving and garnish with extra green onions if desired.
