Line a large baking sheet with parchment paper or foil and coat lightly with vegetable oil spray.
With vegetable oil spray, oil a large bowl and a rubber spatula
In a large deep pot with a fitted lid, add popcorn kernels and oil. Stir to coat and combine. Cover.
Place pot over moderately high heat. Cook, shaking the pot continuously, until all the kernels have popped, about 6 to 8 minutes. You will hear as the popping slows down. Stop as soon as they stop! You don't want to let it burn!
Transfer the popped popcorn to the large oil prepared bowl. Carefully remove the ones that didn't pop.
Using the same deep pot, combine the corn syrup, sugar and water. Turn heat to moderately high. Stir to combine.
Cook, undisturbed, until the mixture develops a light caramel color, about 10 minutes. Careful not to let it burn.
Remove the pot from the heat and add the baking soda and butter.
Stir continuously for about 20-25 seconds melting the butter and combining the ingredients as you stir. Be careful here at this point. The mixture will be very hot and quickly rise and become foamy. Continuous stirring helps the foam subside.
Here's my favorite part! Work quickly and very carefully. Pour the caramel over the popcorn and quickly add the nuts so they'll adhere to the caramel goodness.
Using the prepared oiled rubber spatula, stir everything together. You'll want to work quickly so that the popcorn and nuts will be evenly coated with the caramel.
Transfer the crunchy sweet goodness onto the prepared baking sheet. Spreading out the caramel corn as evenly as possible.
Quickly sprinkle the caramel corn with the fleur de sel. Let cool and harden for about 20 minutes.
Break it up into smaller, bite-size pieces and serve.
To serve individually (and to avoid germs from grimey little hands digging into a big bowl), roll fun papers into a cone shape or scoop into fun little cups.