Sprinkle soda over dates, pour boiling water over dates and let stand. Mix butter, egg, brown sugar and walnuts. Add flour, salt, vanilla and dates. Cream together. Bake in a loaf pan at 350 degrees for 45 minutes or until fork comes out clean when testing. This has been a favorite for our family for at least 25 years. I hope all will enjoy it. Merry Christmas to all.