Prepare a large cookie sheet by covering with aluminum foil, parchment paper, or waxed paper.
Place unwrapped candy canes in a large plastic zip-top bag. Crush with a rolling pin or bottom of a small saucepan until you have small pieces. Reserve about 1/3 cup of the crushed candy canes and set aside.
Melt semisweet chocolate chips in a double boiler or in the microwave. If you're using a microwave, heat in 15-second intervals and stir well each time until completely melted. Melt and stir until chocolate is completely smooth.
Pour melted chocolate onto the cookie sheet and spread it into a thin layer with a rubber spatula. Put the cookie sheet in the refrigerator while you melt the white chocolate. Leave in refrigerator for 10-15 minutes or until almost completely set.
Clean the double boiler and add the white chocolate chips, melting them until smooth (or use the microwave method). Add in all but the reserved 1/3 cup of the candy cane pieces and mix well into the white chocolate.
Remove the cookie sheet from the refrigerator and carefully spread the white chocolate over the semisweet chocolate in a thin layer. Sprinkle the 1/3 cup of candy cane pieces on top of the peppermint bark and place cookie sheet in freezer.
Let the bark completely cool in the freezer. Remove bark from the cookie sheet and break it into large chunks.