½cup(113 g or 1 stick) unsalted butter, room temperature
½cup(100 g) granulated sugar
½cup(100 g) packed light brown sugar
1large egg, room temperature
1cupsemisweet chocolate chips
3candy canes, crushed (equivalent to 12 mini candy canes), sifted (see notes)
In a medium bowl, whisk together flour, cocoa powder, baking soda and salt. Set aside.
In the bowl with a stand mixer (or using a hand mixer), combine the butter and sugar. Beat on medium-high speed until light and fluffy, 3 to 4 minutes. Add the egg and peppermint extract. Beat until combined, about 1 minute. Scrape down the side of the bowl as needed.
With the mixer on low, slowly add the flour mixture and mix until just incorporated, 30 seconds. Stir in the chocolate chips and crushed candy canes.
Cover and chill the dough for 30 minutes.
Ten minutes before taking the dough out of the refrigerator, preheat the oven to 350° F and line cookie sheets with parchment paper.
Use a medium cookie scoop to scoop dough, roll into a ball. Slightly flatten the ball and place on prepared cookie sheet. If you want, add a few candy cane bits on top for aesthetics. Repeat with remaining dough and place on prepared cookie sheet 1 1/2 inches apart.
Bake 10 to 12 minutes, until edges are set and the center is still soft. Let cool on the cookie sheets 5 minutes, then transfer to a wire rack to cool completely.