1. Measjure flour, baking powder and salt into sifter.
2. Beat 'butter or margarine with 1 cup of the sugar until fluffy in a large bowl with an electric mixer at high speed; beat in eggs and orange rind. Sift in flour mixture, a third at a time, blending well. Chill until firm.
3. Roll out dough to a 16-inch square on a lightly floured pastry cloth or board; sprinkle with remaining 1/4 cup sugar. Cut into 4-inch squares. Place, 1 inch apart, on large cookie sheets.
4. Bake in hot oven (400°) 8 minutes, or until firm. Remove cookies with spatula to wire racks to cool. Top with orange frosting, if you wish.