Preheat your oven to 350°F (175°C).
In a mixing bowl, combine the softened butter and granulated sugar. Beat until light and fluffy, about 2-3 minutes.
Add the egg, vanilla extract, and coffee extract to the butter-sugar mixture. Mix until well combined.
In a separate bowl, whisk together the flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Fold in the mini chocolate chips until evenly distributed.
Portion out the dough onto a baking sheet lined with parchment paper, leaving space between each dough ball.
Bake for 10-12 minutes, until the edges look set but the centers may appear slightly underbaked.
Let cool on the baking sheet for about 5 minutes before transferring to a wire rack to cool completely.