Preheat your oven to 350°F (175°C).
In a large mixing bowl, cream together the softened butter and 1 1/2 cups of granulated sugar until light and fluffy, about 2-3 minutes.
Add the room temperature egg and vanilla extract, and beat until fully incorporated.
In a separate bowl, whisk together the all-purpose flour, baking powder, and Kosher salt.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Using a spoon or cookie scoop, portion out the dough into balls about 1.5 inches in diameter, and roll each ball in the remaining 1/4 cup of granulated sugar.
Place the dough balls onto a baking sheet lined with parchment paper, spacing them about 2 inches apart. Bake for 10-12 minutes, until the edges are lightly golden.
Let the cookies cool on the baking sheet for about 5 minutes before transferring them to a cooling rack.
