1/2 cup butter
2 1/4 cups brown sugar
1 cup white corn syrup
1 15oz can sweetened condensed milk
1 teaspoon vanilla
1-2 teaspoons salt (fine sea salt)
3 gallons popped popcorn (1.5 cups of kernels)
Prepare the popcorn; I use an air-popper. The popcorn doesn't require extra butter or oil, since you'll be covering it in caramel.Use a cooling rack placed on top of a baking sheet to spread the popcorn over and let any un-popped kernels fall through. Set aside popcorn in several large bowls.
Combine the first 3 ingredients in a medium sauce pan, stir well and bring to a boil over medium heat.
Add sweetened condensed milk slowly and simmer stirring constantly. Bring almost to soft ball stage (about 220 degrees), remove from heat and add vanilla and salt. Pour over popcorn and slowly turn over to cover popcorn in caramel. Makes about 20-30 popcorn balls.