In a large mixing bowl, beat the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.
Mix in the vanilla extract and peppermint extract until fully incorporated.
In a separate bowl, whisk together the all-purpose flour, unsweetened cocoa powder, and salt to combine evenly.
Gradually add the dry ingredients into the butter mixture, mixing on low speed or folding with a spatula until just combined.
Preheat your oven to 350°F (175°C). Scoop tablespoon-sized balls of dough and place them 2 inches apart on the prepared baking sheet. Using your thumb or back of a spoon, press an indentation into the center of each dough ball.
Fill each indentation with a few chocolate chips, pressing them lightly into the dough. Bake for 12-14 minutes until edges are set but centers look slightly soft.
While cookies are still warm, sprinkle crushed peppermint candies over the chocolate chip centers to help them stick and slightly melt.
Transfer cookies to a cooling rack and let cool completely before serving.
