Line an 8 x 8-inch pan with parchment paper and set aside.
In a microwave safe bowl or stovetop, heat up your chocolate chips until melted. Pour into the lined pan and spread out using a rubber spatula. Let sit at room temperature for 20 minutes.
After 20 minutes, heat up the white chocolate chips until melted. Whisk in the peppermint extract and pour into the pan, on top of the cooling chocolate. Carefully spread it out over the top. If using candy canes, sprinkle over the top.
Let the peppermint bark sit at room temperature until firm. Alternatively, you can let it cool for 30 minutes, then refrigerate it for another 30 minute.