Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine softened cream cheese and ranch dressing until smooth.
Add the shredded chicken and buffalo sauce to the bowl, mixing well.
Stir in half of the cheddar cheese and all of the blue cheese (if using).
Transfer the mixture to a baking dish, spreading it evenly.
Top with the remaining cheddar cheese.
Bake in the preheated oven for 20 minutes or until bubbly and golden.
Remove from the oven and let it cool for a few minutes.
Garnish with chopped green onions.
Serve warm with tortilla chips.