Place scallion, oil, habaneros, ginger, molasses, garlic, thyme, all spice, cardamom, and salt in a food processor or blender and puree. Transfer 1/2 cup mixture to slow cooker; reserve remaining mixture.
Add chicken to slow cooker and coat evenly with scallion mixture. cover and cook until chick is tender, about 4- 6 hours on low.
Position oven rack 10 inches from broiler element and start broiler. Place a wire rack in a foil lined bake sheet and coat with vegetable spray.
Transfer chicken, skin side down onto rack. Brush chicken with half of reserved scallion mixture and broil until lightly charge and and crisp, about 10-15 minutes.
Flip chicken over, brush with remaining scallion mixture and continue to broil until lightly charred and crisp on second side, about 5-10 minutes.
Serve with lime wedges.
