Step 1: Prepare the Baking Sheet

1. Line a baking sheet (about 11×17 inches) with parchment paper, leaving some overhang for easy removal later.

Step 2: Melt the Dark Chocolate

1. In a microwave-safe bowl, melt the dark chocolate in 30-second intervals, stirring after each interval until smooth. Alternatively, you can use a double boiler.
2. Pour the melted dark chocolate onto the prepared baking sheet and spread it into an even layer using a spatula.

Step 3: Chill the Dark Chocolate

1. Place the baking sheet in the refrigerator for about 15-20 minutes, or until the dark chocolate is set.

Step 4: Melt the White Chocolate

1. In another microwave-safe bowl, melt the white chocolate in the same manner as the dark chocolate, stirring until smooth.
2. Stir in the peppermint extract into the melted white chocolate.

Step 5: Pour the White Chocolate

1. Remove the baking sheet from the refrigerator. Pour the melted white chocolate over the set dark chocolate and spread it into an even layer.

Step 6: Add Crushed Peppermint

1. Immediately sprinkle the crushed peppermint candies evenly over the white chocolate layer, pressing them down gently to adhere.

Step 7: Chill and Break

1. Return the baking sheet to the refrigerator for another 10-15 minutes, or until the white chocolate is fully set.
2. Once set, lift the bark out of the baking sheet using the parchment paper overhang. Break it into pieces of your desired size.