Scotch Shortbread
["2 1/2 c. flour", "1/8 tsp. baking soda", "2/3 or 1/2 c. sugar", "1/2 lb. salted butter, softened"]
["Cream sugar and butter.", "Add flour slowly with baking soda. Press onto cookie pan and smooth out with glass cup.", "Prick all over.", "Bake at 325\u00b0 for 45 minutes. Cut into squares while hot."]
["flour", "baking soda", "sugar", "butter"]