The story goes that Wacky Cake came into being during World War II, when home bakers wanted to make dessert without breaking into precious rations. A combination of cheaper ingredients – vinegar, vanilla, oil, and water – was used in place of milk and eggs, which not only created a moist, chocolaty cake, but reduced the overall price drastically. Even today, Wacky Cake costs a little over a dollar to make, and is just ever-so-slightly more complicated than using a boxed mix.
Incidentally, Wacky Cake is also excellent for vegetarians, vegans, and kids with dairy allergies. Top it with a little powdered sugar, and you're good to go.