A whoopie pie is like a sandwich, but made with two soft cookies with a fluffy white filling. Traditional whoopies pies are made with vegetable shortening, not butter. The original and most commonly made whoopie pie is chocolate. but cooks like to experiment, and today pumpkin whoopie pies are a favorite seasonal variation. The recipe for whoopie pies has its origins with the Amish, and in Lancaster county, Pennsylvania, it is not uncommon to find roadside farm stands offering these desserts. Amish cooking is about old recipes that have fed families for generations, with no trendy or cross-cultural fusions or mixtures. These cake-like whoopie pies were considered a special treat because they were originally made from leftover batter. According to Amish legend, when children would find these treats in their lunch bags, they would shout "Whoopie!"