Spatchcock the chicken by first removing the backbone with kitchen shears. Flip the chicken skin-side up, and press down on the breast to snap the breastbone so it lays flat. Season the chicken generously on all sides with about 2 tablespoons of the Nashville Hot Chicken Seasoning.
Preheat the smoker or grill for indirect cooking at 300°F.
Place the chicken bone-side down in the smoker and allow it to cook undisturbed for 45 minutes. Check the temperature, and allow it to continue to cook until the breast meat registers 165°F internal temp. Remove the chicken and tent it with loose foil for a few minutes.
Using a grill-safe sauce pan, add the butter, and 1 tablespoons of the Nashville Hot Chicken seasoning and guajillo chile powder. Place this into the smoker and let it melt, stirring the spices together into a sauce.
Shred the chicken completely when it’s cool enough to handle, and pour in 1 tablespoon of the spicy butter to season it.
Build the sandwich. Slice the entire loaf of Hawaiian rolls with a serrated knife and cut the loave evenly with a horizontal cut. Separate the top from the bottom, giving you two large pieces of bread. Add in generous amounts of the shredded chicken, followed by the slices of cheese, and pickles. Place the top of the bread back on, and pour the rest of the spicy butter sauce all over the top. Use a pastry brush to baste the bread evenly on top.
Place the entire loaf of bread back into the smoker and increase the heat to 350°F. Roast for about 10-15 minutes until you can visibly see the cheese melting and the bread browning.
Remove from the smoker and allow to cool for 2 minutes before serving.