Preheat oven to 225 degrees.
Line a large baking sheet with parchment paper, making sure the paper overhangs all side of the pan. Pour all semi-sweet and milk chocolate chips on to parchment-lined pan. Toss the chips together to mix, and then spread into a single layer.
Place pan of chocolate chips in the oven for 4-5 minutes.
KEEP AN EYE ON THE CHOCOLATE. You are looking for the chips to be *just* melted. The chocolate chips will retain their shape, so watch for the chips to start looking glossy. That will be the indicator that they’ve melted. If you leave them in too long, the chocolate will scorch and turn grainy.
Once the chips have melted, remove the pan from the oven.
Using an offset spatula, gently mix and smooth the chocolate chips so they fill the pan with a single layer of melted chocolate.
Sprinkle the white chocolate chips on top of the melted chocolate.
Leave them alone for 3-4 minutes while they melt.
Using a butter knife or offset spatula, carefully swirl the tip of it through the melted white chocolate chips creating whatever designs you like. The more you swirl the knife through the pan, the more you’ll mix the chocolates together.
Remove wrappers from candy canes and place them in a resealable bag. Using a small pan or rolling pin, crush the candy canes into very small pieces.
Sprinkle the crushed candy cane pieces over the melted chocolate.
Let the pan sit overnight, or until the chocolate has hardened.
Using the parchment paper that’s overhanging the pan, lift the peppermint bark out and place it on a cutting board.
Using a sharp knife, cut the bark into pieces.