Greek Cognac Cookies

1
Place butter in mixer bowl and mix until smooth.
2
Scrape down sides and gradually add the sugar, and blend until well incorporated.
3
Scrape down sides and add the egg yolk and cognac, and mix well.
4
Gradually add the flour and mix until well combined.
5
Cover with waxed paper or plastic wrap and refrigerate at least 3-4 hours, or freeze up to 2 weeks.
6
Preheat oven to 325º.
7
To form the cookies, break off small pieces and roll into 1-inch balls.
8
Place on ungreased cookie sheet.
9
Bake until very lightly browned, about 20-25 minutes.
10
Cool for 2 minutes and remove to a rack.
11
When cooled, sprinkle with additional confectioners' sugar.