Preheat the oven to 350 F. Line 2 baking sheets with parchment paper or silicone baking mats.
Microwave the butter in a large, microwave-safe bowl for about 40 seconds. Butter should be about 90% melted.
½ cup butter
Whisk the butter until it is completely melted.
Add the sugars; mix until well-combined.
¾ cup brown sugar, ¼ cup granulated sugar
Stir in vanilla and peppermint extracts and egg until incorporated.
1 teaspoon vanilla extract, ½ teaspoon peppermint extract, 1 large egg
Add the flour, cocoa powder, baking soda, and salt. Please read the recipe note about properly measuring flour.
1 ⅓ cups all-purpose flour, ⅓ cup unsweetened cocoa powder, ½ teaspoon baking soda, ½ teaspoon kosher salt
Mix dough until just combined. Dough should be soft and a little sticky but not overly sticky.
Stir in peppermint bark cookie chips.
¾ cup peppermint bark cookie chips
Scoop out 1.5 tablespoons of dough (medium cookie scoop) and place 2 inches apart on baking sheet.
Bake for 7-10 minutes, or until cookies are set. They will be puffy and still look a little underbaked in the middle.
Notes
Butter: This recipe uses melted butter. I prefer to use salted butter, but you can use unsalted butter if you prefer.
Sugars: This recipe uses both brown sugar and granulated (white sugar). You can use either dark or light brown sugar. Dark brown sugar will give you a slightly richer flavor.
Peppermint extract: Be sure to get peppermint extract and not spearmint.
Measuring Flour: If you aren’t weighing your ingredients, I can’t recommend that enough. If you are using measuring cups, be sure to sift or stir the flour before measuring. Flour packs easily and using too much flour in cookies will give you dry, crumbly dough and cookies that don’t spread.
Salt: Kosher salt is a larger-grain salt that isn’t as “salty” as table salt. If you’re using table salt, be sure to use 1/4 teaspoon.
Peppermint bark chips: If you can't find a peppermint bark chip blend, you can use peppermint chips or a mix of chocolate chips, white chocolate chips, and peppermint candy cane pieces.