Directions

1. Preheat oven to 350 degrees. Place butter and sugar in a medium bowl; beat with a wooden spoon until combined. Beat in egg yolk, vanilla, baking powder, and salt. Add flour, and mix until a dough forms.
2. Scoop out level teaspoons of dough, and roll into balls (chill dough briefly if it becomes too soft to handle). Place balls on baking sheets, 2 inches apart.
3. Bake, rotating sheets halfway through, until edges are firm and cookies are dry to the touch (do not let cookies color), 10 to 12 minutes.
4. Remove from oven; gently press a candy corn into center of each cookie (surface of cookies may crack slightly). Cool on sheets 1 minute; transfer to a rack to cool completely.