01 - Preheat the oven to 350°F.
02 - In a large bowl, combine softened cream cheese, sour cream, ranch dressing, buffalo hot sauce, garlic powder, and black pepper; mix until smooth.
03 - Fold in shredded chicken, mozzarella, and blue cheese if using until thoroughly combined.
04 - Spread the mixture evenly into an 8x8 inch baking dish.
05 - Bake for 20 to 25 minutes until the dip is hot and bubbling.
06 - Remove from oven and let cool for 5 minutes.
07 - Serve warm with fresh celery sticks.