Shred the chicken and add it back into the cast iron skillet. Adjust stovetop heat to medium-low.
Set 2 handfuls of the 3 cups shredded cheese aside (use cheddar or blend of mozzarella and cheddar). Add the remaining cheese to the skillet along with 8 oz cream cheese, ¾ cup sour cream, ¼ cup ranch, salt, and garlic powder. Blend until smooth and melted.
Top the skillet with the cheese that has been set aside.
Bake at 350℉ for 25 minutes. Adjust the heat to "broil" for the last 3 minutes for a more golden crust on top.
Serve with tortilla chips, veggies, or crackers. Enjoy!