Preheat oven to 175°C (350°F) and line baking sheets with parchment paper.

In a small bowl, dissolve the instant espresso powder in hot water and set aside to cool.

In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, approximately 3 minutes.

Add the egg, vanilla extract, and cooled espresso liquid to the butter mixture and beat until well combined.

In a separate bowl, whisk together the flour, baking soda, and salt.

Gradually incorporate the dry ingredients into the wet mixture, stirring until just combined.

Fold in the chocolate chips by hand.

Scoop rounded tablespoons of dough onto the prepared baking sheets, spacing them 5cm apart.

Bake for 9 to 11 minutes, or until the edges are lightly browned but the centers still appear soft.

Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.