Reroll remaining dough and cut out cookies again. Place on ungreased cookie sheets. Bake at 350 degrees F. for 8 to 10 minutes. Cool completely on wire racks. Remove from heat but keep mixture over hot water.
Place cookies on waxed paper line cookie sheets.
Keep refrigerated until ready to use. In a large bowl, combine butter, confectioners' sugar, and egg yolk. Beat until creamy. Drop by heaping teaspoonfuls onto ungreased cookie sheets. Bake at 350 degrees F. for 8 to 10 minutes.