Preheat oven to 275°F (135°C).
Score the pork belly skin with a sharp knife, making shallow cuts to help render the fat.
Rub the pork with salt, black pepper, smoked paprika, garlic, and ginger, making sure to coat evenly.
Place the pork belly in a baking dish, skin-side up, and roast for 2.5 to 3 hours, allowing the fat to render slowly.
In the last 30 minutes, brush the pork with a mixture of maple syrup, soy sauce, and apple cider vinegar.
Increase oven temperature to 450°F (230°C) and roast for another 15 minutes to crisp up the skin.
Let the pork rest for 10 minutes before slicing. Serve with your choice of side dishes.