This recipe can be made with either corn syrup or cane syrup. Cane syrup tastes a lot better, but is not widely available in the US.
4 quarts plain popped corn
1 c pecans, whole or large pieces
1 c sugar, brown
1/2 c syrup, cane or light corn
1/2 c butter, unsalted
1/2 tsp. salt
1/4 tsp. baking soda
Preheat oven to 250F. Grease three baking sheets with butter. After popping the corn, remove all the unpopped kernels by placing in a bowl, shaking it back and forth, and then carefully pouring the popped corn into another bowl, leaving the seeds behind. Add nuts to corn.In a medium sauce pan, combine sugar, syrup, salt and butter. Bring to a simmer over medium heat. Reduce heat to low and simmer for 5 minutes without stirring. Remove from heat, add soda and stir to combine. Immediately pour half of the caramel over the corn and gentle fold together. Repeat with the remainder of the syrup. Spread evenly on baking sheets. Bake on lower racks in oven for 1 hour, stirring every 15-20 minutes. Cool completely, at least one hour. Break the popcorn apart and place in a bowl to serve or a bag to store.