STIR together corn and cream cheese in large bowl. Stir in chicken, chiles, chili powder and 1 cup of the cheese.
CUT each biscuit into 8 pieces. Add biscuit pieces to chicken mixture; stir gently to mix. Spoon into sprayed 13x9-inch (3-quart) glass baking dish.
BAKE at 375°F 15 minutes. Sprinkle with remaining 1 cup cheese. Bake an additional 12 to 15 minutes or until edges are deep golden brown and center biscuit pieces are no longer doughy. Top with sour cream.