I added an extra layer of finely crushed peppermint in-between the dark and white chocolate layer for extra crunch. You could also flavor the dark or white chocolate with peppermint extract if you want even more peppermint flavor.
My bark turned out a bit marbled because the white chocolate I used didn't melt to the same consistency as the dark; instead it turned into more of a paste, which required more spreading. So even though I had refrigerated and hardened the dark chocolate before I put the white over top, the spreading I had to do melted some of the dark chocolate and I got a marbled finish. It still looks ok though and the taste was not effected at all.
You can use any kind of chocolate you want, just make sure it's something you would want to eat plain since this isn't going to be melted and put into a cake or chopped and added to cookies. Also aside from peppermint you could add pretty much anything you want to chocolate bark. I was thinking about doing a dark chocolate, dried cherry and sliced almond one as well but then got a bit lazy.
2 bars dark chocolate broken into chunks (I like to use 70%)
1* bar white chocolate (Lindt or Ghiradelli work well)
3- 4 medium candy canes crushed
1 cookie sheet
1 sheet parchment paper or a silpat baking mat
*I like a thinner white layer because I don't like white chocolate as much, but you could do even amounts
Place candy canes in a freezer safe plastic bag (the plastic on freezer bags is thicker and can withstand the candy cane pieces' sharp edges). Use a rolling pin or mallet to smash the candy canes into small pieces. Melt dark chocolate in a double boiler. After all the chocolate is melted pour it onto a parchment covered baking sheet. You can pour it all in one spot, then spread it into the desired shape with a spatula. Take about 1/3 of the candy cane pieces and sprinkle evenly over the dark chocolate. Refrigerate until hard. About 15- 20 minutes.
5 minutes before you take out the dark chocolate begin melting the white in a double boiler. Once the white is melted take the hardened dark chocolate out of the fridge and pour the white the white over, spread lightly as needed to cover the dark chocolate evenly. (Hopefully you have better luck than me, but marbled bark is... artistic?) Once the white is spread, sprinkle the remaining candy cane bits evenly over top. Place back in the refrigerator to harden.
Once hard cut the bark into uneven chunks with a sharp knife. It is probably best to store it in the refrigerator after it is cut.