In a large mixing bowl, combine icing sugar, condensed milk, peppermint flavoring, and 2 tablespoons of water. Stir until a stiff paste forms.

Dust a clean surface and rolling pin with icing sugar. Roll the peppermint paste to about 0.5 cm thick.

Using a 4 cm round cutter, stamp out rounds and place on a parchment-lined tray. Let dry for 30 minutes.

Melt dark chocolate over a saucepan of simmering water until smooth. Let it cool slightly.

Transfer the melted chocolate into a piping bag and drizzle over each peppermint round.

Refrigerate the decorated rounds for about 10 minutes until the chocolate sets firmly.

Once set, serve on a decorative plate or store in an airtight container for up to two weeks.