Use kitchen scissors to halve the marshmallows. If the scissors get sticky when cutting marshmallows, lightly coat them with nonstick cooking spray or dip them in hot water.
Layer undrizzled cookies between pieces of waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months. Thaw cookies, if frozen. If desired, drizzle cookies with caramel ice cream topping just before serving.