01 - Line an 8x8-inch baking dish with parchment paper, leaving overhang on the sides for easy removal.
02 - In a medium saucepan over low heat, combine the peanut butter and maple syrup. Stir constantly until melted and smooth, about 2 to 3 minutes.
03 - Remove the saucepan from heat and gently fold in the lightly crushed corn flakes until every piece is evenly coated with the peanut butter mixture.
04 - Transfer the mixture into the prepared baking dish and press firmly into an even, compact layer. Place in the freezer for 20 to 30 minutes until fully set and firm.
05 - Set a heatproof bowl over a pan of barely simmering water. Add the dark chocolate chips and coconut oil, stirring gently until completely melted and glossy.
06 - Remove the peanut butter slab from the freezer and lift it out using the parchment overhang. Cut into 12 even bars using a sharp knife.
07 - Using a fork or dipping tool, submerge each bar into the melted chocolate, tapping gently to let excess drip off. Place each coated bar onto a parchment-lined tray.
08 - Refrigerate the coated bars for at least 20 minutes, or until the chocolate shell is fully hardened and set.