Preheat the oven to 350°F. Line a large baking sheet with parchment paper and set aside.

Sift together the all-purpose flour, cocoa powder, baking soda, and salt in a medium bowl. Set aside.

Cream together the butter, light brown sugar, and granulated sugar for 2-3 minutes, using a handheld mixer on medium speed, or until light and fluffy.

Add the whole egg, egg yolk, vanilla extract, and peppermint extract to the bowl and mix just until fully incorporated.

Add the dry ingredients to the wet ingredients and mix on low just until combined. The dough will be thick.

Fold in the semi-sweet chocolate chips until evenly distributed.

Using a 2 ½ tablespoon scoop, scoop out 8-9 dough balls onto the prepared baking sheet leaving 2-inches between each cookie.

Bake on the center rack of your oven for 10-12 minutes or just until the center of the cookie is set.

Sprinkle the tops of each of the warm cookies with crushed candy cane for garnish if desired.

Allow the cookies to cool on the baking sheet for 3-4 minutes before transferring them to a wire rack to cool completely.

Repeat steps 7-10 until all the cookies have been baked and cooled. Transfer to a platter and serve.