Simmer pineapple juice, brown sugar, ketchup, lime juice, soy sauce, garlic, and ginger in a medium saucepan until thickened and measures about 1 ½ cups, about 10 minutes. Season with salt and pepper to taste.

Spray slow cooker with vegetable oil spray. Transfer ½ cup of the sauce to the slow cooker; reserve remaining sauce separately. Season chicken with salt and pepper, add to slow cooker, and coat evenly with sauce. Cover and cook until chicken is tender, 4 to 6 hours on low.

Preheat oven to 450F. Transfer chicken, skin side up, to an aluminum foil lined baking sheet; discard braising liquid.

Brush chicken with some reserved sauce and baking, brushing with more sauce every few minutes, until it has a deep, mahogany color, 20 to 30 minutes. Serve hot.