Sift together into a medium sized bowl the flour, sugar and vanilla. Work in the margarine with a spoon or hands until well blended. Add chopped pecans and mix well.
Shape dough into 1 inch balls and put on ungreased pans. Bake in a preheated 325 degree F (165 degrees C) oven for about 25 minutes or until pale brown. When slightly cool roll or shake in confectioners' sugar. Store in an air tight container.
