Prepare 8x11 pan by lining with aluminum foil. Spray foil with non-stick spray.
Stir syrup and sugar in medium-size saucepan over medium heat. Stir constantly approximately 5 minutes or until sugar dissolves. Remove from heat and stir in peanut butter until well combined. Pour peanut butter mixture over cereal in a large bowl. Mix well. Pour in to prepared pan. Press down until top is smooth and even.
Melt chocolate and shortening and stir until smooth. Pour over cereal bars and quickly spread until thin. Allow chocolate to harden about 30 minutes.