Place the unwrapped candy canes in a sealed zipped-top bag and roll or bang with a rolling pin or meat mallet until crushed. Set aside.

Combine bittersweet chocolate, semi-sweet chocolate and ½ teaspoon oil in the top of a double boiler over just barely simmering water. Stir frequently, scraping down the sides and bottom of the bowl with a rubber spatula to avoid scorching until chocolate is melted. Remove from the heat and stir in ½ teaspoon peppermint extract.

Pour melted chocolate into the prepared baking pan. Using an offset spatula or spoon, spread into a thin, smooth, even layer. Place the baking pan in the refrigerator for 10–15 minutes or until almost completely set. If it sets completely, the bark layers will most likely separate.

We'll repeat the steps from the bottom layer, but this time with the white chocolate.

Combine white chocolate and remaining ½ teaspoon of canola oil in the top of a clean double boiler over just barely simmering water. Stir frequently, scraping down the sides with a rubber spatula to avoid scorching until chocolate is melted. Remove from the heat and stir in remaining ½ teaspoon peppermint extract.

Pour melted white chocolate on top of the bottom layer. Using an offset spatula or spoon, spread into a thin, smooth, even layer.

Sprinkle evenly with crushed candy canes.

Refrigerate the bark until fully set, about 1 hour.

Once hardened, remove it from the pan and peel off the parchment or foil. Break or cut into pieces of your desired size. If refrigerated for more than 3–4 hours, let it sit at room temperature for 10–15 minutes to soften slightly before breaking or cutting with a sharp knife to prevent the layers from separating.