1. Sift together flour, baking powder and salt onto waxed paper.
2. Beat butter and sugar in bowl until smooth. Beat in egg, orange rind and juice. Add flour mixture, a third at a time, stirring well after each addition.
3. Shape dough into ball; flatten slightly. Wrap in plastic wrap. Refrigerate for several hours or overnight.
4. To bake, heat oven to 350 degrees F. Lightly grease baking sheets. Roll out half of dough on floured surface to generous 1/8-inch thickness. Cut into shapes, using Halloween cookie cutters, 1-1/2- to 5-3/4-inch. Place cookies 1/2 inch apart on prepared baking sheets.
5. Bake in 350 degrees F oven for 9 minutes or until light golden around edges; cookies should not brown. Transfer cookies to rack to cool. Repeat with second half of dough and scraps.
6. Prepare Royal Icing.Decorate cookies:
7. Using small fine-tipped paintbrush, coat cookies with thinned icing. Let stand until dry. Decorate cookies with thicker icing, piping with pastry bag fitted with writing tip.
1. Beat meringue powder or powdered egg whites, confectioners sugar, sifted, and water in bowl until peaks form, 10 minutes (makes 3 cups). Divide icing in half. To make base coat for glaze: Thin half with water, a drop at a time, until consistency of sour cream. Use thicker second half for piping. Tint icing with food colors.