Melt dark chocolate in a microwave or double boiler until smooth.

Stir in peppermint extract.

Pour melted chocolate onto a parchment-lined baking sheet, spreading it to your desired thickness.

Melt white chocolate and drizzle it over the dark chocolate layer.

Use a knife or toothpick to swirl the white chocolate into the dark chocolate.

Sprinkle crushed peppermint candies on top.

Let it cool and harden at room temperature or refrigerate until set.

Break into pieces and serve.