Shortening and ripe banana should measure 3/4 cup. (The recipe originally calls for 3/4 cup of shortening, but you can replace most of that with banana, or applesauce. You can also replace the shortening with oil.) Beat shortening, sugars, egg, water and vanilla together until creamy. Sift together flour, salt and soda; add to creamed mixture; blend well. Stir in oats. Drop by teaspoonsful onto greased cookie sheets. Bake in preheated moderate oven (350 degrees). 12 to 15 minutes. (For variety, add chopped nutmeats, raisins, chocolate chips or coconut.) Makes 5 dozen.