Place the coconut oil, cacao, salt and maple syrup in a small jug and whisk together until smooth.
Line 2 12-hole mini-muffin tins with cupcake or chocolate liners.
Pour a little chocolate into each one to fill them about a third of the way.
Put the chocolate in the freezer for 30 minutes to set.
Spoon about half a teaspoon of peanut butter in the middle of each one and if it was firm peanut butter, pour the chocolate over the top to cover it. If the peanut butter was a bit runny you will have to freeze them again until it is firm.
Refrigerate the finished chocolates to set and store in the fridge until serving.