Tape parchment paper to your countertop or a baking sheet. I prefer counter top, it's easier to spread the chocolate.
Fill a pot half way with water and bring to boil. Place a heat proof glass bowl onto of the pot. This is your double boiler.
Add the dark chocolate and peppermint extract and let the chocolate melt. Stir with a spatula to help it melt.
Once melted, remove bowl from the pot with oven mitts. The steam will escape and burn you, so be careful.
Pour the chocolate onto the parchment paper and spread evenly into a rectangle shape making it ¼cm thick. Let cool completely. It should be hard.
Repeat same melting process with the white chocolate.
Pour onto the dark chocolate and spread evenly.
Sprinkle with crushed candy cane and let cool.
Once cooled, meaning it should be completely hard - no soft spots. Break or cut the bark into pieces.
Store in an airtight container or decorative box.