Whisk together the flour, espresso powder, baking powder, and salt. Set aside.
Place the chopped chocolate and butter in microwave-safe bowl. Microwave until melted, stirring every 30 seconds. Set aside to cool slightly.
Using an electric mixer on medium speed, beat the brown sugar and chocolate until light and fluffy. Add the eggs, one at a time, beating well after each addition. Set aside.
Reduce the mixer speed to low, and gradually add the flour mixture to the chocolate mixture. Beat until smooth. Stir in the chocolate chips.
Cover the dough with plastic wrap. Refrigerate about 4 hours.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper or silicone liners.
Using a tablespoonful of dough at a time, roll the dough into balls. Place two inches apart on baking sheets. Bake one pan at a time for 9 to 10 minutes, or until browned around the edges.
Cool the cookies on the pans for 5 minutes, and then transfer the cookies to a wire rack to cool completely.
Sprinkle with confectioners’ sugar before serving.
Notes
For tips, step-by-step photos, and extra details, be sure to read the full post above before starting. It’s packed with helpful info to answer common questions!