Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 2-3 minutes using an electric mixer.
Add the egg and vanilla extract to the butter and sugar mixture and beat until well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Using a tablespoon, scoop out dough and roll into balls. Place the dough balls on the prepared baking sheets about 2 inches apart.
Flatten each dough ball gently with the bottom of a glass or your hand to about 1/4 inch thickness to ensure crispiness.
Bake in the preheated oven for 10-12 minutes or until the edges are golden brown and the centers appear set.
Remove from the oven and allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Store completely cooled cookies in an airtight container to maintain crispiness.