Preheat oven to 350.
Cream the butter, then gradually add the sugar, beating well. Mix the
flour, salt, and baking powder together and add to the first mixture,
combining well. Roll out the dough until it is 1/4 inch thick. Cut into
rectangles. Place each on an ungreased cookie sheet, prick with a fork
several times and bake for 13-15 minutes.
Makes about 2 dozen.