In a large mixing bowl, mix together peanut butter and powdered sugar
Crush cornflakes in a blender with food processor attachment
Add crushed cornflakes to the peanut butter mixture and stir well until evenly coated
Line an 8x8-inch pan with parchment paper and spread the cornflake and peanut butter mixture evenly into the pan
Freeze for a few hours
Remove from pan and slice into rectangular bars
Return to freezer immediately and freeze an extra 30-60 minutes before coating
Melt chocolate with coconut oil in a double boiler or in 30 second intervals in the microwave, stirring between intervals
Use a fork to coat each bar in melted chocolate, letting excess drip off
Transfer to a parchment paper-lined tray
Return to freezer for 30 minutes to let chocolate firm up
Remove from freezer and enjoy
