Add olive oil to pan then cook onion until tender.
Next saute mango until tender.
Add mango, lime or lemon juice and mango nectar or orange juice, brown sugar, honey and all spices to blender or food processor and grind until smooth. If it needs to thin a bit more, add a little bit more juice.
Pour marinade into a large ziploc bag and submerge chicken in marinade. Seal and refrigerate for at least 4 hours and up to 8 hours.
Preheat oven to 425 degrees and line a baking sheet with non stick foil or parchment paper.
Remove chicken from marinade and season on both sides with remaining salt and pepper.
Bake chicken on first side for 15 minutes then turn over. For more flavor, feel free to baste chicken with marinade during cooking. Cook for another 10-15 minutes or until chicken is completely done, marinade is sticky on chicken and it is browned.
Allow the chicken to marinate in the jerk sauce for at least 4 hours in the refrigerator.