My favourite way to make this cake is as a double layer cake. Not only do you get the added benefit of extra frosting between the layers, it's also easier to ensure the cakes cook evenly and stay perfectly dense. If you bake the cake as one large single cake, it may dry out slightly around the edges as it will take longer to cook. However, it is still absolutely delicious as a single layer cake and perfect if you only have 1 large baking tin.