Pop the popcorn using an air popper (or on the stove with oil if you don’t have an air popper). Place popped popcorn in a large bowl or foil roasting pan, stirring lightly. The unpopped kernels will sink to the bottom so they can be easily removed. Sprinkle chocolate covered espresso beans over the popcorn.
Cover one to two sheet pans with foil or parchment paper.
In a large saucepan, combine sugar, Kahlua, butter, vanilla, and salt. Heat over medium heat, stirring constantly. Continue to cook until sugar melts and caramel becomes a pretty brown (caramel) color, about 15 to 20 minutes. Once it melts and turns a dark caramel color, act fast because it scorches quickly.
Add the baking soda (I measure it first and put it in a little bowl so I can add it all at once) and keep stirring. Be careful as it foams up quickly and almost doubles in quantity. Quickly remove from heat, pour over the popcorn and espresso beans and stir quickly to coat all the popcorn.
Spread the caramel corn out on foil lined sheet pans and allow to cool at least ten minutes before eating. Add more chocolate covered espresso beans if desired.