Cream butter and sugar. Add egg yolk and beat smooth. Add flour and stir until just blended
Place on board and knead lightly until soft and smooth. Place in 9x15 pan, pat down evenly, prick with fork (all over dough evenly)
Bake in slow oven 325 about 1 hour, (watch as ovens vary)
Cut in 1 1/2" squares while hot.
Recipe submitted by Marilee on 11/30/99