Prepare a bain-marie by placing a heat-prooof bowl over a pan of boiling water. The bottom of the bowl must not touch the water! Melt the coconut oil and chocolate piece. Remove from the heat once melted.
Pop the bars from the silicone mould. Use 2 spoons to pick the bars up, place into the melted chocolate mixture, turn over until all sides are coated, remove the bar from the bowl and place on a rack to dry. Place a plate or piece of paper under the rack to catch any drips.
Continue until all bars are coated in chocolate.
The bars will dry quickly as they will be cold from the freezer, enabling the chocolate to set.
Once they have set, use a sharp knife to cut each bar in half.
Keep in the fridge for a week or in the fridge for 2 months. Best eaten at room temperature so remove from the fridge for 10 or so minutes before eating - if you can stand to wait that long!!