Preheat oven to 375 degrees.
Beat butter and sugar until light and fluffy. Add egg, flour, salt and vanilla. Stir in nuts.
Drop batter by rounded tablespoonfuls onto well-greased cookie sheets, flattening to 2-in. discs (cookies will spread about six in., so place far apart).
Bake for 6-9 minutes or until caramel-colored and firm.
Cool 1 minute. Working quickly with spatula, ease 1 cookie at a time from baking sheet. Keeping top of cookie on the outside, form into a cornucopia shape.
Place cornucopia seam-side down on a plate to harden. Cookies harden as they cool, so you may need to place in oven for 30 seconds as you go along to make them more pliable.
Fill with candy corn or other treats to serve.