1. Pat the 3-pound pork belly thoroughly dry with paper towels, ensuring no moisture remains on the skin.

2. Score the skin in a crisscross pattern, being careful not to cut into the meat. For ultimate crispiness, use a sharp fork or a specialized pork pricking tool to prick the skin hundreds of times, creating tiny holes.

3. Rub coarse sea salt generously over the skin, ensuring it gets into all the scores and pricks. Follow with a thin, even layer of baking powder on the skin side.

4. Place the pork belly, skin-side up, on a wire rack set over a baking sheet. Refrigerate uncovered for at least 8 hours, or preferably overnight, to further dry out the skin.

5. Preheat your oven to 300°F (150°C). Roast the pork belly for 2-2.5 hours, allowing the fat to render slowly. Drain any excess rendered fat.

6. Increase the oven temperature to 400°F (200°C) and continue roasting for another 30-45 minutes, or until the skin is puffed, golden brown, and incredibly crispy. Keep a close eye to prevent burning.

7. Remove from the oven, let rest for 10-15 minutes before slicing and serving.