Line a large rimmed baking sheet with parchment paper or a silicone baking mat. Set aside.

Coarsely chop the Oreo cookies. Reserve about 1/4 cup of the chopped cookies for the topping.

In a microwave-safe bowl, melt the white chocolate in 30-second increments at 50% power, stirring vigorously after each interval until completely smooth and melted.

Stir the peppermint extract and green food coloring into the melted white chocolate until you reach your desired shade of green.

Gently fold the larger portion of the chopped Oreo cookies into the colored chocolate mixture until evenly combined.

Pour the mixture onto the prepared baking sheet and spread it out evenly with a spatula to about 1/4 inch thickness.

Immediately sprinkle the reserved 1/4 cup of chopped Oreos over the top, pressing them down lightly to adhere.

Place the baking sheet in the refrigerator for 30-45 minutes (or freezer for 15 minutes) until the bark is completely firm and set.

Remove from the fridge and break the large sheet into irregular pieces using your hands or a blunt knife. Serve immediately or store in an airtight container.