Line an 8 x 8 baking dish with parchment paper. Melt the dark chocolate in a microwave-safe bowl. Do 30-second intervals, stirring after each until smooth.
Spread the melted chocolate onto the prepared baking dish and spread it evenly with a spatula. Place it in the fridge to set for 15-20 minutes.
Melt the white chocolate bar using the same microwave method. Spread the white chocolate over the dark chocolate layer.
Place the unwrapped candy cane in a zip-up bag and use a meat mallet or pan to break into small pieces. Sprinkle the crushed candy cane pieces over the white chocolate.
Place the peppermint bark in the fridge for an hour to set completely.