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 mostly 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 egg until incorporated.
1 teaspoon vanilla 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, ¼ teaspoon salt
Mix dough until just combined. Dough should be soft and a little sticky but not overly sticky.
Stir in chocolate chips.
½ cup semisweet chocolate 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.
Gently press an unwrapped candy into the center of each cookie.
22 Andes mint candies
Let it sit for about 5 minutes to soften.
Carefully spread the melted mint over the cookie.
Remove to a wire rack to finish cooling.
Notes
Butter - I use salted butter. If you're using unsalted butter, increase the total salt to 1/2 teaspoon.
All-purpose flour - It's important to properly measure the flour. Too much flour will give you a crumbly dough or cookies that don't spread. To properly measure the flour, weight it or sift or stir it to break it up. Lightly spoon into a measuring cup and level.
Baking the cookies: It's important to slightly underbake the cookies. Slightly underbaking the cookies helps to keep the soft.