To make the bars, place the desiccated coconut, coconut oil and maple syrup in a bowl and use a spoon or fork to mash them together until well mixed. Press into a 24cm x 24cm tin lined with greaseproof paper and place in the freezer for 20–30 minutes, until solid.
Meanwhile, to make the topping, melt the cacao butter in a small saucepan over a medium heat and then transfer to a mixing bowl. Add the cacao powder and whisk together until there are no lumps. Add the maple syrup and whisk again. Add the liquid stevia if a sweeter taste is desired.
Remove the tin from the freezer and cut the mixture into eight bars. Dip each bar into the dark chocolate mixture. Lay the bars out on a piece of greaseproof paper and place in the fridge for 30 minutes to allow the chocolate to set.