PREPARATION:

1. Combine butter, granulated sugar, brown sugar and egg yolk in medium bowl. Add flour, baking powder and salt; mix well. Cover; refrigerate until firm, about 4 hours or overnight.
2. Preheat oven to 350°F.
3. Roll dough on floured surface to 1/4-inch thickness. Cut into desired shapes with cookie cutters. Place on ungreased cookie sheets.
4. Bake 8 to 10 minutes or until edges begin to brown. Remove to wire racks; cool completely.