Cream togther margarine, sugars, eggs, vanilla and oil. Sift dry ingredients together. Gradually add to creamed mixture; mix well. Chill dough at least two hrs., but preferably overnight. Roll into 1" balls and place on ungreased baking sheets, 2" apart. Flatten with glass dipped in be frosted with white icing and decorated with sugar crystals. Note: Providing the dough has been thoroughly chilled, these cookies keep their shape extremely well. ----