1/3cuppineapple juice(apple juice could be substituted)
1/4cuplow sodium soy sauce
freshly ground black pepper, to taste
6fresh pineapple rings(cut about 1/2" thick)
4Tbspbrown sugar, divided
Place chicken in a 6 or 7 quart slow cooker. In a mixing bowl, whisk together ketchup, pineapple juice, low sodium soy sauce, honey, molasses, liquid smoke, coconut extract, ginger, onion powder, garlic powder and black pepper. Pour sauce over chicken in slow cooker, cover with lid and cook on low heat for 5 - 6 hours.
Remove chicken from slow cooker, shred and set aside. In a medium saucepan, whisk together cold water and cornstarch, pour in sauce from slow cooker and add tomato paste.
Bring mixture to a boil over medium high heat, stirring frequently, then reduce heat and simmer 30 seconds, stirring constantly, until thickened. Return chicken to slow cooker (or the mixing bowl) and pour sauce over chicken, toss to evenly coat. Serve warm on hamburger buns, along with optional glazed or grilled pineapple and optional diced green onions (grilled red onions would be good too).
Working in 2 separate batches, melt 1 Tbsp butter in a 10 inch non-stick skillet. Sprinkle 1 Tbsp brown sugar among one side of 3 pineapple rings (about 1 tsp per each), add pineapple to skillet (brown sugar side down) and saute over medium high heat until golden on bottom about 3 minutes.
Sprinkle another 1 Tbsp over the tops of pineapple rings in pan (again 1 tsp per each), then flip and cook opposite side until lightly browned about 3 minutes. Repeat this process with remaining 3 pineapple rings.