In a mixing bowl, combine icing sugar, condensed milk, and peppermint flavoring. Mix until a stiff paste forms, adding water as needed.

On a sugared surface, roll out the peppermint paste to about 0.5 cm thickness and use a round cutter to stamp out 24 rounds.

Transfer the rounds to a parchment-lined baking tray and allow them to dry for about 30 minutes.

Melt the dark chocolate in a heat-proof bowl over simmering water, stirring until smooth.

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

Refrigerate the decorated peppermint creams for about 10 minutes, or until the chocolate is set.