I've been looking for a way to make sweet and salty popcorn using air popped corn. I couldn't really find one, but they all seemed to have a few things in common.
This version makes a crispy caramel that won't get soggy.
1 cup popcorn kernels
1 cup sugar
1/4 cup butter
Pop the corn in an air popper. Salt to taste.
Over medium-high heat, melt the sugar until it becomes a dark amber.
Stir in the butter until it smoothes out.
Pour over the popcorn and stir/toss to coat.