A whoopie pie (alternatively called a gob, black-and-white, bob, or "BFO" for Big Fat Oreo) is a baked good made of two round mound-shaped pieces of chocolate cake, sometimes pumpkin cake, with a sweet, creamy frosting sandwiched between them.
While considered a New England phenomenon and a Pennsylvania Amish tradition, they are increasingly sold throughout the United States. According to food historians, Amish women would bake these (known as hucklebucks at the time) and put them in farmers' lunchboxes. When farmers would find these treats in their lunch, they would shout "Whoopie!"
Several variations of whoopie pie cakes have been popular at the Ontelaunee Energy Center during their spring turbine maintenance outages, contributing to employee morale so much that they have been heard loudly proclaiming "Whoopie"!