In a large bowl, combine brown sugar, soy sauce, minced garlic, grated ginger, and lime juice. Mix well until sugar begins to dissolve. Add chicken and marinate in the refrigerator for at least 30 minutes, or up to 2 hours.

Preheat your preferred cooking method: grill to medium-high heat (375°F), oven to 375°F (190°C), or slow cooker on low/high.

For grilling, place marinated chicken on the grill and cook for about 6-7 minutes per side, until internal temp reaches 165°F. For baking, transfer to a lined baking sheet and cook for 25-30 minutes. For slow cooker, cover and cook on low for 4-5 hours or high for 2-3 hours until fork-tender.

In a saucepan, heat reserved marinade over medium heat until simmering. Stir in pineapple chunks and let bubble for 5-7 minutes until thickened.

Once chicken is cooked, let it rest for 5 minutes. Adjust sauce sweetness/acidity with lime juice or soy sauce if desired.

Slice the chicken, drizzled with warm pineapple sauce, and garnish with fresh cilantro. Serve with coconut rice or salad.