Mix together curing ingredients (salt, black pepper, brown sugar, curing salt, maple syrup, red pepper flakes) and rub all over skinless pork belly.
Coat the pork belly with the curing paste and place it in a ziplock bag in the refrigerator for 6 days, flipping daily.
After 6 days, remove the pork belly from the bag, rinse it under cold water to remove the cure, and pat it dry with paper towels.
Season with fresh cracked black pepper and place it back in the refrigerator on a wire rack above a baking sheet, uncovered, for 12-24 hours to form a pellicle.
Preheat the smoker to 165°F and fill the hopper with applewood pellets.
Smoke pork belly until internal temperature reaches 155°F (around 6 hours).
Chill smoked pork belly in the refrigerator before slicing it to desired thickness.
Fry slices in a cast iron skillet until crispy. Serve and enjoy!