Preheat the oven to 170°C (338°F).
Cream the butter and powdered sugar until smooth.
Add almond flour and corn starch, and mix well.
Shape the dough into small balls.
Place them on a baking sheet lined with parchment paper.
Bake in the oven at 170°C for 15 minutes.
Let cool, then roll the cookies evenly in powdered sugar.