Place the semisweet chocolate chips in a medium bowl and microwave in 30-second intervals, stirring after each, until fully melted and smooth.
Place a sheet of parchment paper on your 11.8"x15.75" Blue Carbon Steel Rectangular Baking Sheet. Spread the melted chocolate evenly onto the sheet. Refrigerate for exactly 10 minutes to partially set. The edges should firm up while the center remains slightly melted. Avoid letting it harden completely, as this can prevent the white chocolate layer from adhering.
Microwave the white chocolate chips in a medium bowl in 30-second intervals until melted and smooth (you can add a tablespoon of oil to the chocolate to make it smoother and thinner). Stir in the peppermint extract.
Spread the melted white chocolate evenly over the semisweet chocolate layer. Sprinkle crushed candy canes on top before the chocolate hardens. Chill in the fridge for about 20 minutes or until fully set.
Remove the bark from the fridge and let it sit at room temperature for 20 minutes. Use a sharp chef’s knife to cut it into pieces, pressing straight down to keep the layers intact. Serve and enjoy!