Do you remember that caramel corn mixed with peanuts that would come in a small cardboard box and have a toy hidden inside? Well, this is my version, with a Gullah spin. I add a mixture of nuts and sesame seeds (known as benne seeds in Gullah and Low Country cooking) to the buttery, sweet caramel corn.
Preheat the oven to 200 degrees F. Grease or butter two large, rimmed baking pans. Combine the popcorn, peanuts, pistachios and sesame seeds in a very large bowl or roasting pan.
Melt the butter in a medium saucepan over medium heat. Add the brown sugar, corn syrup, peanut butter and salt. Bring to a boil, stirring constantly, then cook until the mixture is completely emulsified and there is no visible melted butter around the edge of the pan, 1 to 2 minutes. Remove from the heat and stir in the vanilla and baking soda. (The mixture will puff up.)
Pour the mixture evenly over the popcorn mixture and toss well to coat. Divide the popcorn between the two prepared pans, spreading in an even layer. Bake the popcorn for 1 hour, stirring every 15 minutes and rotating the pans so it cooks evenly. Let cool in the pans, about 20 minutes. Break into pieces to serve.
Make sure to remove any unpopped kernels before pouring on the caramel.