01 - Line a 9x13 inch baking sheet with parchment paper.
02 - Melt the dark chocolate in a heatproof bowl set over simmering water or microwave in 30-second intervals, stirring until smooth.
03 - If desired, stir ¼ tsp peppermint extract into the melted dark chocolate.
04 - Pour melted dark chocolate onto the prepared sheet and spread evenly to a ¼ inch thickness. Chill for 15–20 minutes until set.
05 - Melt the white chocolate using the same method; optionally add remaining ¼ tsp peppermint extract.
06 - Once dark chocolate is firm, pour melted white chocolate over it and spread evenly with an offset spatula.
07 - Immediately sprinkle crushed peppermint candy evenly over the white chocolate and gently press into the surface.
08 - Refrigerate for at least 30 minutes until fully set.
09 - Break or cut into approximately 20 pieces. Store in an airtight container at cool room temperature for up to 2 weeks.