What's your favorite cookie (or biscuit, for any British baking show buffs)? Chocolate chip, ginger spice, or Oreo? Oatmeal-and-raisin, black-and-white, digestive, or florentine? Or do you just prefer the dough? Our choice biscuits and cookies are as diverse as the myriad forms and flavors these chewy treats take, and well they should be. These baked delights have a history as rich as their taste: evidence of biscuit-making dates back to around 4000...