Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.

In a large bowl, cream butter, sugar, vanilla, and peppermint extract until fluffy. Add the eggs and mix until just incorporated.

In a medium bowl, combine the flour, cocoa powder, baking soda, and salt. Add the flour mixture to the wet mixture and mix until just incorporated. Gently fold in chocolate chips and peppermint candy.

Roll the dough into even balls (I made about 30) and place in the refrigerator (or freezer) until well-chilled. (About 30 minutes refrigerator, 15 minutes freezer.) Once chilled, transfer to your prepared baking sheet (about 6-8 per sheet) and bake for 10-12 minutes. Let cool about 2 minutes on the pan before transferring to a wire rack to cool completely.