Butter one side of each slice of bread. Sprinkle half the cheese on the unbuttered side of one slice of bread.
Combine the chicken, Sunbutter, marmalade, sriracha, and basil, mixing well. Scoop this on top of the cheese, top with the remaining cheese and the unbuttered side of the other slice of bread.
Heat a skillet over medium heat. Place the sandwich in the pan, cover, and cook until the bottom slice is golden brown, 2-3 minutes. Flip and cook until the other side is golden and the cheese has melted.