I found this recipe online - didn't save the source - but have had 2 people now ask me for the recipe.
Spray the inside of a large brown paper grocery bag* with Pam. Place 14 cups popped corn in the bag. Salt to taste. Set aside.
1 C brown sugar
1/4 C light corn syrup
1/2 t baking soda
1/2 C (1 stick butter)
Cook mixture over medium heat for 2-3 minutes until mixture is bubbly. Don't overcook. Pour over popcorn in bag. Fold bag top down and microwave on high for 1 minute. Remove bag. Shake well. Microwave another 1 minute. Shake. Empty popcorn onto large cookie sheet covered with waxed paper to cool.
*I ran out of brown bags, so I just made it in a giant plastic container with successful results.