Line baking sheet with foil and set aside. Melt bittersweet chocolate over low heat. Remove from heat and mix in ½ cup candy canes and wafer cookies. Spread mixture on lined baking sheet until flat and even. Melt white chocolate in microwave or at low heat on stove. Drizzle melted white chocolate in zig zag design. Sprinkle rest of candy canes on top. Place baking sheet in refrigerator and chill for at least one hour. Remove and break into pieces.