With a fork or whisk, get all all the lumps out of the cacao powder, then add coconut oil, maple syrup, peppermint extract, vanilla extract, and salt. Mix thoroughly. Pour into a plastic wrap lined baking dish.*
Put in the fridge about 20-30 minutes, or until starting to solidify. Add 1 of the crushed candy canes so that it's evenly distributed. The reason you refrigerate it first is so that the crushed candy cane doesn't sink to the bottom.
Refrigerate another 30 minutes or so, and while the mixture is not totally solidified, sprinkle the other crushed candy cane on top so that it sticks to the top.
My dish is 7 ½" x 9 ½", and the bark came out to almost ½" thick. For thinner bark, use a larger dish.