Line a jelly roll pan covered with aluminum foil.
In a microwave safe bowl, add in milk chocolate chips and coconut oil. Melt in the microwave for 30 seconds, remove and stir, and continue to heat in the microwave in 15 second intervals until completely melted and smooth.
Add in the peppermint extract and stir to combine.
Evenly spread the chocolate onto the prepared jelly roll pan.
Place in the refrigerator to chill for 30 minutes.
Using the same microwave method, melt the white chocolate chips and coconut oil. Once completely melted and smooth, add in ¼ cup of the crushed peppermint candies and stir to mix well.
Remove the jelly roll pan from the refrigerator and evenly spread the white chocolate over the chilled milk chocolate.
Sprinkle the remaining crushed peppermint candies on top of the chocolate and lightly press down to ensure the candies stick.
Place in the refrigerator for an hour to chill.
Once chocolate has set, break the bark into small pieces.