I'm making a cake in the shape of a coffee cup. Does anyone have an idea of how to make the top area look like coffee with a cream latte design? You know, like a swirl or heart? I don't think it would look right to just pipe white on top of the base brown and pull a toothpick through. I think this look could be achieved with royal icing, but I don't think I want the whole top of a cake covered in royal icing.