Cinnamon that is mixed with brown sugar. It is much darker therefore "negro" like in appearance, hence "neegra".
It is often baked into the crust of ludicrously sweet soul food, served with a side of watermelon and some Kool-Aid or Grape Drink with far too much sugar.
Thusly resulting in a diabetic comma known as a Neegracinnacoma. These are all technical terms.
The chicken n' waffles had too much NEEGRACINNAMON in them and he slipped into a NEEGRACINNACOMA. It's just awful.