Preheat your oven to 350°F (175°C).
Shred the cooked chicken into bite-sized pieces and set aside.
In a large mixing bowl, combine the shredded chicken with the buffalo sauce and stir until fully coated.
Add cream cheese, ranch dressing, garlic powder, onion powder, salt, and black pepper to the bowl and mix until well combined.
Transfer the mixture into a greased 9x13 inch baking dish, spread evenly, and sprinkle shredded cheddar cheese on top.
Bake for 20-25 minutes until the cheese is bubbly and golden brown.
Let it cool for a few minutes and garnish with chopped green onions before serving.