Line a 9×12 rimmed sheet pan with aluminum foil or parchment paper.
In a microwave-safe bowl, melt the dark chocolate in the microwave in 30-second intervals, stirring in between.
Mix in 1/2 of the peppermint extract, then pour into the prepared pan. Place in refrigerator to chill.
In a separate microwave-safe bowl, melt the white chocolate in 30-second intervals, stirring in between. Stir in remaining peppermint extract.
Remove pan from refrigerator and pour the white chocolate over the dark chocolate. Before it sets, sprinkle crushed candy canes over the top, gently pressing into the chocolate.
Chill until hard, about 30 minutes. Break into pieces and serve. Enjoy!