Preheat oven to 350° F and line baking sheet with parchment paper.
In a medium bowl, mix together flour, cocoa, salt, and baking soda then set aside.
With a mixer, cream butter and sugars together until smooth. Add in eggs, one at a time. Next, add in the vanilla and peppermint extract and mix until combined.
Add flour mixture to butter/sugar mixture and beat until just combined. Stir in chopped peppermint bark.
Scoop the dough into rounded tablespoons and place on prepared baking sheet, about 2 inches apart.
Bake cookies for 10 minutes and set aside on cooling rack.