Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or lightly grease it.
In a large mixing bowl, combine the granulated sugar, brown sugar, and softened butter. Cream them together using an electric mixer or whisk until light and fluffy.
Add in the egg and vanilla extract, and mix until well incorporated.
In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, mixing just until combined. Be careful not to overmix, as this can affect the texture.
Using a cookie scoop or tablespoon, scoop out portions of dough and roll them into balls. Roll each ball in the extra granulated sugar to coat.
Place the cookie dough balls on the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 8-10 minutes, or until the edges are lightly golden. The centers may look slightly underbaked—that's okay! They will continue to cook on the sheet after being removed from the oven.
Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.