In a mixing bowl, cream butter and sugar together. Gradually stir in the flour.
Turn onto a lightly floured surface and knead until smooth, about 3 minutes.
Pat into a 1/3" thick rectangle, measuring 8 x 11". Cut into 2 x 1" rectangles.
Place 1" apart on ungreased baking sheets.
Prick with a fork. Bake at 300° for 25 minutes or until bottom begins to brown.
Cool for 5 minutes; remove to a wire rack to cool completely.