Preheat oven to 325. In a medium bowl, mix together flour, salt, soda, ground ginger, crystallized ginger and allspice and set aside. In a large bowl, mix together sugar and butter until creamy. Add egg and molasses and beat until fluffy. Add flour mixture and mix just until combined. Do not overmix. Chill dough 1 hour. Shape dough into balls about 1 inch in diameter. Place on ungreased cookie sheets about 2 inches apart. Bake 25 minutes and transfer cookies to cool, flat surface to cool.