Put the popped popcorn and nuts in a greased roasting pan and set it in a 250 degree oven to warm. Warm popcorn is easier to coat.

In a large saucepan, heat the sugar, Kahlua and vinegar until very hot. Add the butter and bring to a boil, stirring often. Insert a candy thermometer and continue boiling, stirring often (I stopped a couple of times, but stirred here and there to prevent burning) and bring the mixture to 300 degrees F – hard crack stage. Immediately remove from heat.

Pour over the warm popcorn and nuts and stir to coat. At this point it will be very chewy. Let it cool completely. If you cooked it to hard crack, it will crisp when it is completely cool.

Eat as is or douse with more liqueur and eat immediately.