Place the popped popcorn into a large roaster ~ I used a foil throw away one so clean up was easy, otherwise, you will want to heavily grease your roasting pan.
In a small pot, combine the butter, corn syrup, brown sugar & dry apple cider mix. Cook on high until boiling. Reduce heat to medium-high & let boil for 5 minutes. Remove from heat and add the vanilla.
Drizzle the caramel over the popcorn, stirring to coat. Bake for 1 hour, stirring every 15 minutes.