Preheat oven to 350 degrees F and line baking sheets with parchment paper
In a large bowl, combine the melted butter and light brown sugar and whisk to combine.
Add the egg and vanilla extra and whisk until smooth
Add the flour, cornstarch, baking soda and salt to the egg mixture and whisk until fully combined
Using a spatula, fold the mini chocolate chips into the cookie dough
Scoop the chocolate chip cookie dough using a teaspoon or a small ice cream scoop (approximately .4 ounces) and line the balls of dough on the prepared baking sheets leaving about 1 inch apart to allow the cookies to spread a little
Bake the cookies in the preheated oven for 5-6 minutes
Remove the cookies from the oven and allow them to cool for 5-10 minutes before removing them from the baking sheet
Serve or store in an airtight container