Add the chocolate and coconut oil to a small saucepan and heat over low heat, stirring until fully melted.
Pour the chocolate mixture into the molds (filling them up only 1/3 full).
Place in the freezer for 20 minutes.
Remove from the freezer and add the peanut butter mixed with coconut sugar on top, followed by the remaining chocolate mixture (filling the chocolate to the top of each mold).
Place back in the freezer for at least 30 minutes, or until the chocolate has hardened.