See how to make an easy cake from scratch. Black Magic Cake gets its dark color from an surprise ingredient that you probably associate with breakfast more than dessert. Watch the video for a tip on how to mix the liquid and dry ingredients. As a bonus, you'll find out how to make buttermilk if you don't have any on hand. This extra-dark cake is a favorite at Halloween, but it's so tasty you'll find other days to make it.