Heat oven to 375°F. Line pan with foil. Cover completely with 1 layer of saltines. Bring butter and sugar to a boil; boil gently 2 minutes.

Immediately pour over saltines, spreading evenly.

Bake 12 minutes. Remove from oven and pour chocolate chips evenly. Wait a few minutes (2 to 3) and spread melted chips evenly. Refrigerate until cold and hardened. Remove foil and break into bite sized pieces. Keeps well in a tin.