Put the oil in a large, deep pan with a lid. Turn the heat up to medium, add 2 kernels of corn, and cover.
When the kernels pop, remove the lid and pour in the remaining popcorn kernels. Cover and shake the pot, holding the lid on. Cook over medium heat, shaking the pot occasionally, until the popping sound stops after about 5 minutes.
Meanwhile melt the butter and stir the brown sugar into it. (this helps the brown sugar stick to the popcorn).
Pour the popcorn into a large bowl, drizzle on the melted butter and sprinkle in the curry powder, cayenne, and a good shake of salt.
Recipe by Love and Lemons at https://www.loveandlemons.com/sweet-curry-popcorn/