Preheat grill and coat with nonfat cooking spray. Place 1 Tbsp lime zest, 2 Tbsp fresh lime juice, 1 Tbsp brown sugar, 1 Tbsp fresh grated ginger, 1 tsp salt and 1/4 tsp cayenne pepper in a resealable plastic bag; Add fish to bag. Allow to marinate at room temperature for 20 min, turning once. Meanwhile, in a second plastic bag, place 1 Tbsp brown sugar, 1 Tbsp ginger, and 1/2 medium pineapple, cut lengthwise into 1/2-inch-thick spears. Seal bag and allow to marinate for 5 min; remove pineapple and add resulting juices to fish bag. Grill pineapple until heated through, turning once, about 8 minutes. Remove to a serving platter; cover with foil to keep warm. Cook fish over direct heat, brushing with marinade, until cooked through.