Put 6 tablespoons of unsalted butter and 6 ounces of dark chocolate chips in a microwave-safe bowl.

Microwave and stir in short 20-second bursts until the chocolate is completely melted (around 60 seconds in my microwave). Let it cool.

In a large bowl, combine ½ cup granulated sugar, ½ cup packed light brown sugar, 2 large eggs, ½ teaspoon vanilla extract, and ⅛ teaspoon coffee extract (optional).

Use a hand mixer on medium speed to mix for 5 minutes (set a timer) until the mixture becomes pale, light, and airy.

Mix in the melted butter-chocolate mixture. Set aside.

Mix together ¾ cup all-purpose flour, ¼ cup unsweetened cocoa powder, ½ teaspoon baking powder, and ¼ teaspoon salt in a medium-sized bowl.

Stir the flour mixture into the wet mixture (the dough will be loose).

Refrigerate for 20 minutes until the dough is chilled and firm enough to shape into balls.

Preheat the oven to 350°F and line a baking sheet with parchment paper or a silicone mat.

Use a standard 2-tablespoon cookie scoop to form balls from the dough and place them two inches apart on the prepared baking sheet.

Bake for 14-16 minutes (adjust as needed).

Allow the cookies to sit on the pans for 2-3 minutes before transferring them to a wire rack to cool completely.

Store the cooled cookies in an airtight container.