Place the cream cheese in a food processor and process until smooth. Add the sour cream and pulse to combine.
Roughly chop 6 of the chiles and add them to the processor along with the cumin, onion powder and garlic powder. Process until smooth. Transfer the dip to a bowl.
Chop the remaining 2 chiles. Stir into the dip. Taste, and add salt and pepper as needed.
Refrigerate the dip until ready to serve. Serve with tortilla chips.
