Preheat the oven to 350°F (175°C).
In a large mixing bowl, whisk together the softened cream cheese, Greek yogurt, buffalo hot sauce, and garlic powder until a smooth consistency is achieved.
Stir in the shredded chicken and half of the mozzarella cheese until evenly distributed.
Transfer the mixture into a 9-inch square baking dish or a small oven-proof skillet, spreading it into an even layer.
Sprinkle the remaining mozzarella and the blue cheese crumbles over the top.
Bake for 20 minutes or until the mixture is bubbling at the edges and the cheese on top has melted.
Remove from the oven and garnish with sliced green onions.
Serve warm with celery sticks or whole-grain crackers.