Friendship bread
Amish friendship bread is a type of bread or cake made from a sourdough starter that is often shared in a manner similar to a chain letter. The starter is a substitute for baking yeast and can be used to make many kinds of yeast-based breads, shared with friends, or frozen for future use. The sweet, cake-like Amish cinnamon bread is a common bread that is made from this starter; it is a simple, stirred quick bread that includes a substantial amount of sugar and vegetable oil, with a mild cinnamon flavor. It has characteristics of both pound cake and coffee cake. The flavor of the finished product can be altered by cinnamon being omitted. A common recipe using this starter suggests using one cup of it to make bread, keeping one cup to start a new cycle, and giving the remaining three cups to friends. The process of sharing the starter makes it somewhat like a chain letter. One cup of starter makes one standard loaf of bread. There is no reason to think that the sweet, cinnamon-flavored bread has any connection to the Amish people, although the name is taken from them. According to Elizabeth Coblentz, a member of the Old Order Amish and the author of the syndicated column "The Amish Cook", true Amish friendship bread is "just sourdough bread that is passed around to the sick and needy".
Source: Wikipedia