cinnamon
If you are not using it on fried apples, you're doing it wrong.
When I was camping, as a kid, we'd core an apple, stuff it with nuts, butter, brown sugar and cinnamon, wrap it in aluminum foil, toss it in the fire, wait, then enjoy. Haven't had one in years.
But Mrs. P. often fries apples for breakfast. Good stuff. A bit of nutmeg is good too.