Microwave peanut butter, syrup and sugar in large microwavable bowl on high 3 minutes, stirring every minute.
Pour over cereal in large bowl; mix to coat well. Press into greased foil-lined 13x9-inch pan.
Spread melted chocolate evenly over cereal mixture. Let stand or refrigerate until chocolate is firm. Cut into 24 bars. Store in tightly covered container in refrigerator.