01 - In a mixing bowl, combine powdered sugar, butter, peppermint extract, heavy cream, and salt. Beat with an electric mixer or sturdy spatula until a smooth, pliable dough forms. If the mixture is too sticky to handle, gradually add more powdered sugar until workable.
02 - Scoop out portions of the peppermint dough, approximately 2 teaspoons each. Roll into balls and flatten to 1/4-inch thick discs. Arrange the discs evenly on a parchment-lined baking sheet.
03 - Place the baking sheet in the freezer and chill the peppermint discs for 20 to 30 minutes until firm.
04 - In a heatproof bowl set over simmering water, melt the dark chocolate and coconut oil (if using), stirring occasionally until the mixture is glossy and smooth.
05 - Using a fork, dip each chilled peppermint disc into the melted chocolate, allowing any excess coating to drip off. Place coated patties back onto the parchment-lined sheet.
06 - Refrigerate the finished patties for 15 minutes or until the chocolate shell is firmly set.