Put the very soft butter and powdered sweetener into a small mixing bowl. Blend with a fork until smooth.
Add the room temperature mascarpone and peppermint extract. Continue mixing with the fork until a smooth dough forms.
Portion the peppermint filling with a measuring tablespoon (12g each). Roll into a ball with your hands and flatten on a tray lined with parchment paper.
Freeze for 30 minutes until firm.
Break the dark chocolate into squares (or use sugar free chocolate chips) and put in a small bowl. Melt in a water bath or in a microwave in 30 second intervals.
Using 2 forks, dip the patties one by one in the melted chocolate, then place them onto parchment paper. Option to add sugar free sprinkles, freeze-dried raspberry powder or any other topping of your choice straight away, while the chocolate is still soft.
Place the patties back in the freezer or into the fridge until set, around 10 minutes. Store in the refrigerator.
