Heat oven to 400. separate biscuits. Flatten w/ hand to a 3-1/2" circle, each biscuit. Divide chicken, squash and cheese evenly among circles, placing filling on one side. Fold the empty side over filling. Pinch edges to seal. Spray a baking sheet w/ cooking spray. Place biscuits on baking sheet. Bake 10 min, or until golden. In small bowl, stir together mayonnaise and mustard. Serve biscuits w/ mayo mix and ranch dressing.