When ready to cook, start the Traeger on Smoke with the lid open until a fire is established (4-5 minutes).
Generously rub each rack of ribs with Traeger's Asian BBQ Rub. Place directly on the grill grate and smoke for 1 hour.
Line a large roasting pan with heavy-duty aluminum foil. Once ribs have smoked for 1 hour, add ribs to the pan and increase temperature to 300 degrees.
In a mixing bowl combine hoisin sauce, soy sauce, sake, orange juice, brown sugar, and cayenne. Whisk until the sugar crystals dissolve. Add the garlic, ginger, and the half of whites.
Open grill lid and pour mixture evenly over the ribs in the pan, turning the racks to coat them. Place the ribs meat-side down in the sauce. Cover the pan tightly with heavy-duty aluminum foil.
Roast the ribs until they are tender, about 3 to 3-1/2 hours, or until rib meat pulls away from the bones about 1/2 inch.
Move ribs to a cutting board and let rest. Leave the grill on.
Make the glaze: Strain the cooking juices into a heat-proof container, such as a Pyrex measuring cup, and measure 3 cups. (Discard any solids or extra liquid.) Skim off any excess fat. Add the cooking liquid to a large saucepan or skillet. Stir in the jelly and cider vinegar and bring to a boil on the stove-top over medium-high heat until reduced by one-third. Remove from the heat.
In the meantime, using a sharp knife, slice the rib racks into individual ribs. (Each rack should yield 10 to 13 bones.) Working in batches, add the ribs to the glaze, turning them to coat with tongs. Arrange the ribs directly on the grill grate or return them to the pan they were cooked in and grill for 5 to 10 minutes, turning as needed to warm the ribs and “tighten” the sauce.
Transfer to a platter. Sprinkle with the reserved scallion greens and toasted sesame seeds. Enjoy!