Line a baking sheet with parchment paper, making sure it’s flat and even.
In a microwave-safe bowl, melt the dark chocolate chips in 30-second intervals, stirring in between until smooth and fully melted.
Pour the melted dark chocolate onto the prepared baking sheet, spreading it into an even layer about 1/4 inch thick.
In another bowl, melt the white chocolate chips the same way until smooth. Stir in the peppermint extract.
Drizzle the white chocolate over the dark chocolate layer, using a knife or spatula to swirl them together gently for a marbled effect.
Sprinkle the crushed candy cane pieces evenly over the top, pressing them down lightly with your fingers. If desired, sprinkle a pinch of sea salt for added flavor.
Place the baking sheet in the refrigerator for about 1-2 hours, or until the chocolate is completely set.
Once set, break the bark into irregular pieces and store in an airtight container at room temperature or in the fridge.