Preheat the grill to medium-high and place the limes flesh side down on the grill. Cook for 5 minutes or until there are nice char marks. Set aside. Cut the pineapple into 4 large pieces lengthwise, cutting around the core, then cut into eighths. Skewer the pineapple spears and grill on each side for 2-3 minutes. Once the first side has nice char marks, flip and squeeze the grilled lime juice over the pineapple. Take the fruit off the grill and immediately squeeze more grilled lime juice over the top. Drizzle molasses over the skewers and finally grate some fresh lime zest over the top. That’s it!