This cooking technique infuses the duck with so much flavor.
In a small saucepan, warm marmalade over medium heat until liquified. Remove the pan from heat, and pass the liquid through a fine sieve set over a small bowl. Stir in 4 sprigs of thyme, grated ginger, and pink peppercorns; set the glaze aside.
Preheat oven to 400 degrees. Rinse duck inside and out under cold running water; pat dry. Season cavity with pepper, and stuff with onion, carrot, celery, ginger rounds, remaining 2 sprigs thyme, bay leaf, rosemary, and 1 cinnamon stick. Using kitchen twine and a trussing needle, sew cavity closed, and tie the legs together.
Pour 1/3 of the salt into a Dutch oven slightly larger than the duck. Place duck on salt, and brush duck generously with the glaze. Place the remaining 2 cinnamon sticks on top of the salt. Cover duck completely with remaining salt.
Roast duck until a meat thermometer inserted into thickest part of thigh registers 165 degrees, about 2 hours 15 minutes.
Remove the pot from the oven; let it stand 30 minutes to cool. Carefully invert the pot onto a large cutting board. Break salt away from duck; brush off any excess salt. Remove skin. Transfer duck to a cutting board, carve, and serve.
This roasting method also works well with a 4-pound chicken; adjust the cooking time to about one and a half hours.