Mix the nut butter, sweetener, vanilla, cocoa, and salt in a medium sized pot and melt on low heat.
Put the cereal in a large bowl and pour the chocolate mixture over the cereal. The mixture will be thick and sticky. Stir very well, making sure to coat all of the cereal.
Line a square pan with wax paper and spread the mixture evenly into the pan. Place a sheet of wax paper on top of the mixture, then press down as firmly as you can.
Freeze for at least a half hour before slicing.
Recipe Notes
These treats can be stored in the freezer, in the fridge, or loosely covered in a cool, dry place.