For the hot sauce: Mix together the hot sauce, molasses and butter in a small pot. Heat until combined, then set aside.
For the wings: Whisk together the brown sugar, salt, garlic powder, smoked paprika and pepper in a bowl. Whisk the oil into the dry mixture, creating a loose rub. Set a quarter of the mixture aside to use for brushing.
Slather the wings with the rub. Brush the grill grates with a little olive oil, then add the wings to the grill. Cook, covered, for about 10 minutes, then baste with the reserved rub mixture. Flip and baste with any remaining rub and cook for another 15 minutes. Remove the wings from the grill and toss with the hot sauce in a large bowl. Transfer to a platter and sprinkle with the scallions and parsley, if using.