Prep & Preheat: Preheat the oven to 350°F (175°C). Lightly grease an 8×8-inch baking dish or a 9-inch pie dish.
Combine Dairy & Sauce: In a medium mixing bowl, combine the softened cream cheese, Frank’s RedHot sauce, ranch or blue cheese dressing, half of the shredded Cheddar, and half of the Monterey Jack cheese. Mix until smooth.
Fold in Chicken: Add the shredded chicken to the bowl and gently fold until evenly coated in the sauce mixture.
Assemble: Transfer the mixture into the prepared baking dish and spread evenly. Top with the remaining Cheddar and Monterey Jack cheese.
Bake: Bake uncovered for 20 to 25 minutes, or until the dip is hot, bubbly around the edges, and the top cheese is fully melted.
Serve Let the dip rest for 5 minutes. Garnish with green onions, if using, and serve warm with tortilla chips, celery sticks, or crackers.