01 - Line a 8x12-inch baking sheet with parchment paper.
02 - Melt the dark chocolate in a heatproof bowl over simmering water or microwave in 30-second intervals, stirring until smooth.
03 - Stir 1/2 tsp peppermint extract into the melted dark chocolate.
04 - Pour the dark chocolate onto the prepared sheet and spread evenly to about 1/5 inch thickness.
05 - Refrigerate the tray for 15 minutes to set the layer.
06 - Melt the white chocolate in a clean heatproof bowl using the same method.
07 - Stir the remaining 1/2 tsp peppermint extract into the melted white chocolate.
08 - Pour the white chocolate over the set dark layer, spreading gently to cover evenly.
09 - Immediately sprinkle crushed peppermint candies evenly over the white chocolate layer.
10 - Refrigerate for at least 1 hour until completely firm.
11 - Remove from fridge, break into 16 pieces, and store in an airtight container.