Answer:
I'm a small ring shaped fried cake, often with bavarian cream or fruit filling, and sometimes covered in icing and sprinkles.
You can break it or drink water from it.
They are Dark, and always on the run. without the sun, would be none!
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
Very helpful if you intend to go gently down a river.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?