I don't generally like kettle corn, but I must say I am in love with this version from Melissa d'Arabian.
2 tablespoons canola oil
2 tablespoons unsalted butter
1/2 cup popcorn kernels
4 tablespoons sugar
fine salt, to taste
ground cinnamon, to taste
cayenne, to taste
Get the oil hot over medium heat. (If you do high heat, you will burn the sugar!) Quickly stir in butter, then popcorn, then sugar. Put the lid on and shake it like you mean it!
See full instructions and original recipe here. She even has a video.
The changes I made: 1 added an additional tablespoon of sugar. (hey, I like it sweet!). I do not measure the salt, cinnamon, or cayenne. I spread my popped corn out on a sheet of wax paper and sprinkle with salt, cinnamon and cayenne to my liking.