Preheat your oven to 350°F (175°C).
In a large bowl, cream the softened butter and granulated sugar until light and fluffy.
Add the egg and vanilla extract, mixing until well combined.
In another bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Chill the dough in the refrigerator for 30 minutes.
Roll the dough into small balls and place them on a baking sheet lined with parchment paper.
Flatten each ball slightly with a fork or your fingers.
Bake for 10-12 minutes or until the edges are lightly golden.
Remove from the oven and let cool on a wire rack before serving.