Sift together flour, baking powder and salt. Work butter in a bowl until creamy; gradually add sugar and beat until fluffy. Add egg and vanilla; beat thoroughly. Add sifted dry ingredients to butter mixture and beat until smooth. Cover and chill thoroughly. Heat oven to 350ºF.   Grease cookie sheets lightly with unsalted shortening. Divide dough into small portions and roll out one portion at a time, leaving remainder in the refrigerator. Place one portion on a floured board; cover dough with a sheet of floured waxed paper to prevent sticking, and roll dough to a thickness of 1/8 inch. Cut with a 2-inch cookie cutter. Place cookies 1-1/2 inches apart on the prepared cookie sheets. Decorate if desired. Bake 8-10 minutes, until edges are lightly browned. Remove cookies and cool on wire cake racks. Makes 5-6 dozen cookies.

source: The Great Christmas Cookie Swap Cookbook