Combine dates, baking soda, and boiling water in a small bowl. Cool to room temperature. Sift together the flour, cocoa, and salt; set aside. Cream the shortening and sugar together in a mixing bowl until light and fluffy, using an electric mixer at medium speed. Add eggs, one at a time, beating well after each addition. Blend in date mixture. Then stir in dry ingredients. Pour into a greased 13 x 9 x 2-inch baking pan. Bake in preheated 350 degree F. oven for 35 minutes or until cake tests done. Cool in pan on rack. Cut into squares and serve with a scoop of vanilla ice cream on top.