Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, beat the butter, granulated sugar, and brown sugar until creamy.
Add the eggs, vanilla extract, and peppermint extract, then mix well.
In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients and mix until combined.
Fold in the chocolate chips and crushed peppermint candies.
Scoop dough onto the prepared baking sheet and bake for 10-12 minutes.
Allow cookies to cool on the baking sheet for a few minutes before transferring to a wire rack.