Line a 9x13-inch baking sheet with parchment paper and set aside.
Melt white chocolate chips in a microwave-safe bowl in 30-second intervals, stirring between each, until smooth and completely melted (about 2-3 minutes total).
Stir in peppermint extract until well combined.
Pour melted chocolate onto prepared baking sheet and spread evenly to about ΒΌ-inch thickness.
Immediately sprinkle crushed candy canes over the top, pressing gently to adhere. Add a tiny pinch of sea salt if desired.
Refrigerate for 30 minutes or until completely set, then break into irregular pieces and store in an airtight container for up to 2 weeks.