A fault line cake is a type of cake that features deliberate crevices, typically around the middle of the cake. Instead of carving out actual chunks of cake, lines of buttercream are swiped out and filled with various ingredients such as sprinkles, candy bars, cookies, fruit, or buttercream flowers. The cake is known for its elaborate and artistic appearance, and it has become a popular trend in the world of cake decorating. To make a fault line cake, a rotating cake stand and an offset spatula are typically used to frost the cake smoothly. The design allows for a great deal of creativity and customization, making it suitable for various occasions.