Cream margarine and brown sugar; blend in molasses and water. Combine dry ingredients; stir into creamed mixture. Refrigerate, covered, several hours or overnight. Shape 2 level tablespoons dought into balls; place 4" apart on lightly greased baking sheet. Flatten with bottom of sugared 2 cup glass measure. Bake in a preheated 350 degree oven just until no finger print remains when lightly touched (12-14 minutes). Cool on baking sheet 1 minute. Remove to wire rack to cool. Frost when cooled. Store between sheets of waxed paper in tightly covered container.
Vanilla Cream Frosting: Combine 5 cups sifted powdered sugar, 6 tablespoons half-and-half, 2 teaspoons vanilla and 1/2 teaspoon salt until smooth.
Tips:
For faster measuring, use a level 1/8 cup (2 tablespoon) coffee scoop to measure out the cookie dough.