There is a piping tip I have used and I want to purchase one for at-home use. I used it before at work but I'm not sure what company makes it. I don't have an actual picture of the tip but I have a description and a picture of the end result. The tip had a half sphere inside the nozzle that left a ring/wreath shape. You would end up with a french star with a hole in the middle to fill with whatever you please. The picture of the finished result is attached.