Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.

In a large mixing bowl, beat the softened butter, granulated sugar, and powdered sugar until light and fluffy.

Add the egg and vanilla extract, continuing to beat until smooth.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add this mixture to the wet ingredients, mixing until just combined.

Using a cookie scoop or tablespoon, drop balls of dough onto prepared baking sheets, spacing them about 2 inches apart.

Bake for 10-12 minutes or until the edges are lightly golden. The centers may look soft but will firm up as they cool.

Allow the cookies to cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.