Line a 9x13 inch baking pan with parchment paper, extending the paper over the edges, and spray lightly with cooking spray.

Place candy canes in a sealed plastic bag and crush with a rolling pin until you have a mixture of fine pieces and small chunks. Set aside half for later use.

Melt dark chocolate in a microwave-safe bowl in 30-second intervals, stirring between each interval, until smooth. Add 1 teaspoon vegetable oil and stir to combine.

Pour melted dark chocolate into prepared pan and spread evenly with a rubber spatula. Tap pan gently on counter to release air bubbles.

Sprinkle half of the crushed peppermint candies over the dark chocolate layer and press gently with the back of a spoon. Refrigerate for 20 minutes.

Melt white chocolate in a microwave-safe bowl in 20-second intervals, stirring frequently, until smooth. Add 1 teaspoon vegetable oil and 1/4 teaspoon peppermint extract. Stir well.

Remove pan from refrigerator and pour melted white chocolate over the set dark chocolate layer. Spread evenly with a rubber spatula.

Immediately sprinkle remaining crushed peppermint candies over white chocolate layer and press gently into surface.

Refrigerate for at least one hour until completely set and firm.

Lift bark from pan using parchment paper overhangs, place on cutting board, and break into irregular pieces or cut into squares with a sharp knife.