Cream butter and sugar. Add egg white gradually then fold in flour with salt.
Add vanilla and stir mixture until smooth.
Use cake decorating tube to form mixture into long and narrow oblong shapes about 2 inches long.
Drop each onto slightly greased cookie sheet.
Bake in 375 °F oven 5 to 8 minutes or until light brown. Remove immediately and let cool.
Store in tightly covered jars.