Preheat the oven to 325 degrees F.
Place the pork belly fat-side up in a 9x12 inch baking pan. The pork belly should just fit in the pan and there shouldn't be much room around it.
Use a sharp knife to score the fat on the top of the pork belly. Score the fat into 1 inch (2.5 cm) squares so that you can see how to cut the pork belly once cooked. Make sure that you don't cut all the way through the fat and into the meat, just cut 1/2 way down through the fat.
In a small bowl, combine the cinnamon, clove, star anise, fennel seed, Sichuan peppercorns, salt and black pepper. Once combined, sprinkle the spice mixture over the pork belly. Make sure to rub the spices in and to cover all sides of the meat.
Once the meat is coated in the spice mixture, add the water and bay leaves to the baking dish. Cover the entire baking dish with aluminum foil and bake in the oven for 1 1/2 hours.
After the pork belly has cooked, remove it from the oven and let it cool for 15-20 minutes, until it is cool enough to touch. Remove the pork belly from the pan and place it on a cutting board. Discard the remaining water and bay leaves.
Preheat the broiler to 500 degrees F and move the oven rack to the top of the oven.
Use a sharp knife to cut the pork belly into 1 inch (2.5 cm) cubes, using the score marks as a guide. If there is still a thick layer of fat on top of the pork belly, trim the fat so that there is 1/2 cm of fat on top of the meat. Arrange the pork belly cubes back into the dish, fat side up. It is easy if you lean them against each other in the same order as they were cut.
Place the baking dish under the broiler for 7-10 minutes, or until the pork fat has become golden and crisp. Definitely keep an eye on it so that the fat doesn't burn. Once the fat has become crisp, remove it from the oven.
In a small bowl, combine the maple syrup, rice syrup, Sriracha and sesame oil. Pour the sauce over the pork belly bites, tossing them to fully coat. They don't need to be fat-side up this time, just in an even layer in the baking dish. Place the baking dish under the broiler and broil for 5-7 minutes, tossing every few minutes so that the sauce doesn't burn. The sauce will thicken up and become very sticky.
Once the sauce is sticky, remove the baking dish from the oven and place the pork belly bites onto a serving plate. Garnish with the chopped scallions and sesame seeds and enjoy!