Preheat your oven to 350°F (175°C). This ensures even baking.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Beat in the egg and vanilla extract until well combined.
Add the tablespoon of oil and mix until fully incorporated.
In a separate bowl, whisk together the flour, instant coffee, baking soda, cornstarch, and salt.
Gradually add the dry mixture to the wet ingredients, mixing until just combined.
Fold in the mini semi-sweet chocolate chips.
Using a cookie scoop, portion out the dough onto a prepared baking sheet, spacing them about 2 inches apart.
Bake for about 10-12 minutes, or until edges are lightly golden while centers are soft.
Let the cookies cool on the baking sheet for 5 minutes before transferring to a cooling rack.