Mix molasses, soy sauce, sesame oil and orange zest in a bowl and let the flavours of the glaze develop overnight.
Preheat broiler. Reserve about one quarter of the glaze. Marinate scallops in remaining glaze for 10 minutes, then remove and season with salt and pepper.
Place under broiler for 3 minutes, then remove from oven.
Brush scallops with a little more glaze and finish broiling for another 3 minutes. Brush scallops with reserve glaze when done. Serves 4.