> 2 1/2 cups all-purpose flour
> 1/2 cup unsweetened cocoa powder
> 1 tsp instant espresso powder
> 1 tsp baking powder
> 1/4 tsp salt
> 1 cup (2 sticks) butter, softened
> 1 cup sugar
> 1 large egg
> 2 tsp vanilla extract
> 1 cup semisweet chocolate chips or white chocolate chips
Preheat oven to 350°F. Line 2 large cookie sheets with parchment. In a medium bowl, whisk together the flour, cocoa powder, espresso powder, baking powder, and salt.
In a large bowl, using a hand mixer or stand mixer, cream the butter and sugar 2–3 min., until fluffy. Add the egg and vanilla. Mix well. In batches, slowly add dry ingredients on low speed until combined.
Shape dough into 1-inch balls. Arrange on cookie sheets, spacing 1 inch apart. Bake cookies 8–10 min., until golden, switching racks halfway through. Let cool slightly and transfer cookies to a wire rack to fully cool.
In a small microwave-safe bowl, microwave the chocolate chips in 30-sec. intervals, until melted, stirring in between intervals. Drizzle melted chocolate over cookies.