Beat butter until light and fluffy, about 1-2 minutes. Add in brown sugar and white sugar and beat until combined. Add in egg, vanilla extract, and salt. Mix.

In a separate bowl, mix flour, cornstarch, baking soda, and espresso powder. Slowly incorporate the dry ingredients into the wet ingredients.

Once combined, add in the chocolate chips and mix.

Chill the dough for 20-30 minutes, just to firm it up slightly. (Because I'm impatient, I typically scoop the dough onto trays and pop them into the freezer for about 5 minutes instead).

Preheat the oven to 350 degrees and grease a cookie sheet.

With a medium cookie scoop (about 2 Tbsp of dough per cookie), scoop the dough and spread evenly on the cookie sheets, about 2 inches apart.

Bake for 14-15 minutes, or until the cookies are slightly golden brown.

Enjoy