Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium mixing bowl, whisk together the flour, baking soda, and salt. Set aside.
In another bowl, cream together the softened butter, granulated sugar, and brown sugar using an electric mixer or whisk until light and fluffy.
Add the egg yolk and vanilla extract to the butter mixture, mixing until well combined.
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Do not overmix.
If using, fold in the chocolate chips gently.
Using a cookie scoop or tablespoon, drop small amounts of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 8-10 minutes, or until the edges are golden brown and the centers are set.
Remove the cookies from the oven and allow them to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.