01 - Preheat oven to 375°F.
02 - Combine cream cheese, sour cream, ranch dressing, and buffalo wing sauce in a large mixing bowl. Mix until smooth and well combined.
03 - Fold in shredded chicken, cheddar cheese, mozzarella cheese, garlic powder, and black pepper. Mix thoroughly to distribute ingredients evenly.
04 - Transfer mixture to a 1.5-quart oven-safe baking dish. Smooth the top evenly with a spatula.
05 - Bake for 20 to 25 minutes until dip is bubbling and golden brown on top.
06 - Remove from oven and let cool for a few minutes. Top with chopped scallions and blue cheese crumbles if desired.
07 - Serve warm with tortilla chips for dipping.