What am I?

Tear me off and scratch my head, what once red is now black. What am I?

related riddles

One prisoner I hold who bangs my walls. I’m alarming to all, Yet charming as well. I’m smooth and shiny to all. What am I?

I can be white or dark, I am sweet and sometimes bitter and you see me on a cupcake or in a cookie. What am I?

You buy me to eat, but never eat me. What am I?