1. Line a 9x13-inch baking dish with foil, shiny side up. In a small saucepan over medium-high heat, bring 2 inches of water to a gentle boil.
2. Place a heat-safe bowl over the saucepan (now acting as a double boiler). Don’t let the bowl touch the water! Lower the heat and add ¾ cup of the semisweet chocolate to the bowl, stirring as it melts. Add another ¾ cup chocolate and keep stirring.
2. Once all of your chocolate is melted, add ¾ teaspoon of the peppermint extract and let those flavors socialize for just a sec, then swiftly pour the melted chocolate into the lined baking dish to create a nice even layer. Let that sit for 10 minutes.
3. Repeat the same process with the white chocolate. Use a clean bowl and working with a bit more white chocolate at a time - so begin with 1 cup of white chocolate chunks, melt, and repeat. Add your peppermint extract and then swiftly pour this white layer over the brown layer in your baking dish.
4. Sprinkle with crushed candy canes and allow to firm up. Once solid, break the bark using a knife.