Line a baking sheet with parchment paper and add corn flakes cereal to a large bowl.
Cook sugar and syrup in saucepan over medium-heat, until mixture bubbles. Then stir in peanut butter until dissolved and smooth.
Pour peanut butter mixture over corn flakes and gently stir until combined.
Shape mixture into small round balls and place on parchment paper to harden, about 15 to 25 minutes.
Microwave method: Add sugar, corn syrup and peanut butter in a large glass bowl (or 8 cup measuring bowl) and microwave for about 3-5 minutes until bubbly, stirring often. Then add in cornflakes and gently stir until combined.