1. Preheat the oven to 350 F and line a large baking sheet with parchment paper or a silicone baking mat.
2. In a large mixing bowl, whisk together the flour, cocoa, baking powder, baking soda and salt. 
3. In the bowl of a stand mixer fitted with the paddle attachment, or using a handheld mixer, combine the sugar and butter together and mix on medium-high until the butter is light and fluffy. Add in the eggs, one at a time, mixing in between. Add the vanilla and peppermint and mix on low until combined. With the mixer continuously running on low, slowly adding the flour mixture until a soft dough forms. Stir in the chocolate chips by hand with a large wooden spoon.
4. Divide the dough into two, and shape each portion into a 12 x 4″ (about 1″ high) log on the baking sheet. Place the baking sheet into the oven and bake for 25 minutes. Remove from the oven, and let the biscotti rest for 20 minutes before removing to a cutting board and slicing the biscotti, on the diagonal, into 1″ slices.* The more you angle your knife while slicing, the longer your biscotti will be.
5. Reduce the oven temperature to 325 F and prepare two lined baking sheets. Place the cut pieces of biscotti, cut side up, onto the baking sheets and bake for another 15 minutes. Remove, and allow the biscotti to cool completely before drizzling the cookies with melted chocolate and crushed candy.

Biscotti will keep at room temperature, in an air-tight container for 2 weeks, or up to 3 months in the freezer.