Whisk the cocoa powder into the melted coconut oil a little at a time and then whisk in the other ingredients until smooth.
Use a spatula to smooth it into a small parchment paper lined tray roughly the size of your hand / bit smaller than A5 / approx 17cm x 11cm (we used a glass lunchbox). Place in the fridge to set for 10 minutes.
Use a whisk to blend the ingredients for the mint fudge layer together until smooth.
Smooth over the chocolate layer and set in the fridge.
Slice into squares and enjoy straight from the fridge.