Preheat over to 200ºF/95ºC
Stack a piece of parchment over a piece of aluminum foil (big enough to wrap pork belly). Pat pork belly dry and place on parchment paper. If belly has skin, score the skin in a criss-cross pattern. Sprinkle all surfaces with five-spice, salt, ginger and garlic powder, patting into meat. Wrap pork belly with parchment paper, and then foil. Place in oven on ovenproof dish, fatty side up. Let cook for five hours.
Mix together lacquer ingredients. After five hours of cooking, remove pork belly from oven and increase oven temperature to 325ºF/165ºC.
Remove pork belly from wrapping and place in ovenproof dish, fatty or skin side up. Spoon some of lacquer on top, and place back in oven.
Cook pork belly for one additional hour, removing every 10 minutes to spoon additional lacquer over the pork belly. After one hour of cooking, remove and let sit for 5-10 minutes. Then, move to a cutting board, cut with a sharp knife and serve.