Preheat the oven to 350°F (180°C).
Add both types of sugar and room temperature butter into a mixing bowl. Beat for about 1-2 minutes until well-combined. You can use a hand mixer or a stand mixer fitted with a paddle-shaped attachment.
Add the egg and vanilla extract. Beat for 1-2 minutes or until well-combined.
Stir the flour with baking powder, cocoa powder, espresso powder, and salt in a medium bowl. Add the flour mixture to the mixing bowl. Mix at low speed until half-combined (the flour shouldn’t be fully incorporated at this point).
Add the chocolate chips (or roughly chopped chocolate) to the mixing bowl. Mix at low speed until the chocolate chips are evenly distributed and there are no streaks of flour visible.
Scoop the dough with a 3 Tbsp scoop onto a baking sheet lined with parchment paper at least 2 inches (5 cm) apart.
Bake for 12 minutes. The cookies will be still soft (they will finish baking on the sheet pan). Leave them on the baking sheet to cool, then transfer to a cooling rack.
Enjoy!