01 -
Preheat oven to 180°C (350°F) and line two baking sheets with parchment paper.
02 -
Add softened unsalted butter, light brown sugar, and granulated sugar to a large bowl. Cream with an electric mixer for two minutes, until light and fluffy.
03 -
Incorporate egg yolks, peppermint extract and vanilla into the creamed mixture. Mix on medium speed for two minutes, until pale in color and fluffy.
04 -
Add flour, cocoa powder, baking powder, baking soda and salt and mix until just combined, being careful not to overmix.
05 -
Fold in peppermint chips and chocolate chips until evenly distributed throughout the dough.
06 -
Scoop the dough into 18 equal-sized balls and arrange them two inches apart on the prepared baking sheets.
07 -
Bake cookies for 10-12 minutes (10 for chewier centers, 12 for crispier edges).
08 -
Allow cookies to cool on baking sheets for two minutes, then transfer to a cooling rack for 10 minutes. Optionally sprinkle with crushed candy canes while still warm.