Mix corn syrup and peanut butter in a large bowl until smooth; stir in rice cereal. Press cereal mixture into the bottom of a 9x13-inch baking dish. Cover and freeze until firm.
Cut cereal mixture in half, crosswise. Spread ice cream over half the cereal and press the second half over the ice cream to create a large sandwich. Cover and freeze again until firm.
Cut sandwich into bars and serve or wrap individually with aluminum foil.
