Preheat your oven to 160°C (320°F) to ensure even baking.
In a mixing bowl, cream together the room temperature salted butter and powdered sugar until light and fluffy.
If using, add the pure vanilla extract and mix until combined.
Sift together the potato starch and cake flour in a separate bowl to eliminate lumps.
Gradually combine the sifted dry ingredients with the creamed mixture using a spatula, folding gently until just combined.
Roll the dough into 1-inch balls and place them on a baking sheet lined with parchment paper.
Bake for 12-15 minutes or until the edges are lightly golden.
Let the cookies cool on the baking sheet for a few minutes, then transfer to a wire rack to cool completely. Dust with powdered sugar before serving.
