01 - Set the oven to 350°F (180°C) to prepare for baking.
02 - In a large bowl, blend the softened cream cheese, sour cream, ranch dressing, buffalo hot sauce, garlic powder, and black pepper until smooth.
03 - Fold in the shredded chicken, mozzarella, and blue cheese if using, ensuring an even mixture.
04 - Spread the combined mixture evenly into an 8x8-inch baking dish.
05 - Bake for 20 to 25 minutes until the dip is heated through and bubbling.
06 - Allow the dip to cool for 5 minutes after removing from the oven.
07 - Present warm with fresh celery sticks for dipping.