Line 8 x 8 inch pan with non-stick foil.
Pour the water into a small pot and carefully add the sugar and corn syrup into the center of the pan. Stir with a spoon until it reaches 235º on a candy thermometer.
Remove from heat, stir in the melted butter and pour the mixture over the cereal in a bowl. Stir to coat and press into the pan using a silicone spatula. Stick in the freezer to cool.
For the chocolate peanut butter layer: In a microwave safe bowl, melt the peanut butter and chocolate. Stir to combine and pour over the crust. Stick back in the freezer until firm.
Make the dark chocolate glaze: In a microwave safe bowl, heat the chocolate, corn syrup and butter till melted. Stir and spread over the peanut butter layer. Chill again!
Cut into squares. Keep squares chilled.