What Makes Cookie Crunchy?
The crisp or crunchy texture of a cookie is usually achieved through a combination of ingredients and baking process. The use of granulated sugar and/or brown sugar helps to create a drier dough that will spread less while baking. The addition of baking powder or baking soda helps to lift the dough and create pockets of air, which also contributes to the crispiness of the cookie. Finally, baking the cookies at a higher temperature for a shorter period of time helps to further dry out the dough and create a crispy exterior.