Make the filling: Preheat oven to 375°F. Spray a broiler-safe 13-by-9-inch baking dish with cooking spray. Whisk cream cheese, ½ cup enchilada sauce, and ¼ cup chiles in a large bowl until mostly smooth. Stir in chicken and 1 ½ cups cheese.
Fill and roll the tortillas: Spread ½ cup enchilada sauce evenly in bottom of prepared baking dish. Place tortillas on a clean work surface. Spread about ⅔ cup chicken mixture along center of each tortilla. Roll tortillas to cover filling; place seam side down in baking dish.
Top with sauce and cheese: Stir together remaining enchilada sauce and ¼ cup chiles. Pour over enchiladas, spreading to coat tortillas evenly. Top with remaining 1 ½ cups cheese. Cover with foil.
Bake and garnish: Bake for 30 minutes. Uncover and bake until cheese is bubbly, about 5 minutes. If desired, turn oven to broil and cook, uncovered, until cheese has started to brown, 3 to 5 minutes. Top with avocado, sour cream, and cilantro.
