Line a 9" x 13" with foil. Grease foil with cooking spray

In a medium pan over medium heat, mix corn syrup, sugar, and water. Stir constantly until the mixture has bubbles around the edges of the pan.

Remove from heat and stir in the peanut butter, vanilla, and salt.

Transfer mixture to the baking pan and allow to cool. While the mixture is cooling, melt chocolate in a bowl over barely simmering water while stirring until halfway melted.

Remove from heat and stir until chocolate is very smooth.

Pour melted chocolate over the rice mixture and spread it to a uniform layer. Sprinkle salt flakes evenly.

Let cool and cut into pieces.