I'm a flat circular spongy roll made from yeast dough and eaten toasted and buttered
I'm very tempting, so it's said, I have a shiny coat of red, and my flesh is white beneath. I smell so sweet, taste good to eat, and help to guard your teeth.
Strip the skin under my skin, and my flesh you'll reveal. It tastes sweet and tart, now throw out the peel. What is it?