Line a cookie sheet with parchment paper.
Place the dark chocolate into a medium microwave safe bowl, and microwave in 30 second increments. Stir vigorously after each time in the microwave, until it is smooth and creamy.
Stir in 1/4 teaspoon of the peppermint extract.
Spread the chocolate onto the prepared parchment paper, in a size of about a 9x13 pan.
Place it in the fridge to chill for 8 to 10 minutes, until it's almost set.
Place the white chocolate into another medium sized microwave safe bowl, and microwave in 30 second increments, stirring well after each time.
Stir in the remaining 1/4 teaspoon peppermint extract.
Pour the white chocolate over the dark chocolate, and carefully spread it evenly over the top.
Sprinkle the candy cane pieces evenly over the top of the white chocolate.
Place the pan in the fridge to harden, or let it set at room temperature for several hours until hard.
Break, or cut the bark into pieces, as big or as small as you want.