In a small bowl, whisk the brown sugar, kosher salt, onion powder, garlic powder, celery seeds, and black pepper until the ingredients are evenly distributed. Set aside.
Place the salmon pieces in a shallow bowl and add the dry brine mixture. Press down gently, spreading it to completely cover the fillet.
Place in the fridge for four hours or more. Remember that the longer it stays in the brine, the saltier it will be. Don't be alarmed if your brine turns into liquid. It's pulling moisture from the fish so it can put it back in for a juicier fillet.
Remove the salmon from the brine and rinse under cold water. Pat dry with paper towels.
Place on a cookie sheet topped with a cookie rack - let it dry in the refrigerator for at least 4 hours (preferably overnight) for that shiny look.
Remove from the fridge and glaze with honey, if desired. Season the salmon with coarsely ground pepper, fresh dill, or other herbs and spices to your liking.
Preheat your pellet smoker to 225°F (110°C) using wood such as alder or apple for a subtle, smoky flavor.
Place the salmon directly on the smoker's grate, skin side down. Smoke for 1½-2 hours. Pay attention to the salmon; your goal is an internal temperature of about 130-140°F (55-60℃).
Remove the salmon from the pellet grill and serve with lemon wedges. It pairs beautifully with grilled asparagus and a fresh garden salad.