Pre-heat the oven to 180°C/350°F
Cream butter & sugar in the bowl of a stand mixer or using a hand mixer on high speed until light & fluffy.
Add the egg and vanilla and beat until well combined.
Add flour, cocoa powder, baking powder & salt and mix in well.
Using your hands, form the dough into a ball and place on a lightly floured surface. Using a floured rolling pin roll out the dough until it is approximately 5mm thick. Using a 48mm (1 & 7/8 inch) round cookie cutter, cut out the biscuits and lay out on a lined baking tray.
Bake for 12-14 minutes until the biscuits are starting to crisp up around the edges. Remove from the oven and allow to cool on the tray.
Add the icing sugar, milk & peppermint extract to a medium sized mixing bowl and combine using a spoon until the fondant comes together. If you need to, add slightly more milk and if it becomes too soft, add more icing sugar until you can form it into a ball with your hands.
Take the fondant ball and place on a surface sprinkled with icing sugar. Sprinkle more icing sugar on the top and using a rolling pin, roll out until it is 4-5mm thick. If the fondant sticks to the rolling pin, sprinkle with more icing sugar.
Using the same 48mm (1 & 7/8 inch) round cookie cutter, cut out fondant circles and place them on the cooled biscuits.
Melt the chocolate chips & coconut oil in a medium sized microwave bowl for about 1 minute, stirring every 30 seconds, until melted and smooth.
Have a baking tray lined with baking paper or a silpat liner ready to place the chocolate covered biscuits on.
Take the fondant topped biscuits and dip into the chocolate - make sure you get a good coating of chocolate on each one. Place on the prepared baking tray to set.
Allow the chocolate to harden - if you are in a warmer climate, place them in the fridge for 15 minutes.
Store biscuits in an airtight container at room temperature for 5 days or in the fridge if you prefer.