In a bowl add the rice cakes and use your hands to crush them up. Add in the peanut butter, honey and mix until all combined.
Line a container (17cm x 13cm), add the mixture and use a spoon to press it down so it's all even.
Spread the melted chocolate on top (optional - add some flaky sea salt) and place the slice in the freezer for 1 hour to set.
Slice up and store in the fridge - it lasts around a week