Preheat and prep the pan: Heat your oven to 375°F (190°C).
Lightly oil a 9x13-inch baking dish or line it with foil for easy cleanup.
Prep the peppers: Slice the bell peppers in half lengthwise and remove seeds and membranes. Brush the insides with a little olive oil and season with a pinch of salt and pepper.
Soften the peppers (optional but helpful): Place the pepper halves cut-side up in the baking dish. Bake for 10 minutes to soften slightly.
This helps them cook through without overbrowning the filling.
Make the filling: In a large bowl, combine the shredded chicken, cream cheese, buffalo sauce, garlic, onion powder, diced celery, and half the green onions. Add 1/2 to 3/4 cup shredded cheese. Stir until creamy and evenly mixed.
Taste and adjust with salt, pepper, and more buffalo sauce if you like it spicier.
Add dressing (optional): Stir in ranch or blue cheese dressing for extra tang and moisture. Start with 2 tablespoons and add more if needed.
Stuff the peppers: Spoon the buffalo chicken mixture into each pepper half, mounding it slightly. Press gently so it fills the corners.
Top with cheese: Sprinkle the remaining shredded cheese over each pepper.
Add a little crumbled blue cheese if you love that classic flavor.
Bake: Return the dish to the oven and bake for 18–22 minutes, or until the peppers are tender and the cheese is melted and bubbling.
Broil for color (optional): Switch to broil for 1–2 minutes to get golden, bubbly tops. Watch closely to avoid burning.
Garnish and serve: Let the peppers rest for 5 minutes. Top with the remaining green onions, a drizzle of buffalo sauce or ranch, and fresh herbs if you like.
Serve warm.