Preheat oven to 350°F and line two baking sheets with parchment paper.
In a large bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy. Beat in egg and vanilla until smooth.
In another bowl, mix together flour, cornstarch, baking soda, and salt. Gradually add to the sugar mixture until fully incorporated. Mix in the mini chocolate chips, reserving a few to press in the tops if desired.
Scoop dough by the teaspoon and roll into a ball. Place on the baking sheet, leaving a small amount of space between dough balls. Gently press the dough balls with your fingers and press in extra chocolate chips if desired.
Bake for 6-8 minutes, until lightly golden brown. Let cool on the baking sheet for 2 minutes before removing to a wire rack to cool completely.
Nutrition information is an estimate based on online calculators and provided as a courtesy. Any nutritional information should be used as a general guideline only.