Mix brown sugar, salt, and cayenne pepper.

Cover the salmon fillet completely with the brown sugar mixture in a baking dish and refrigerate for 4.5 hours.

For Glaze: Combine soy sauce, orange juice, ginger, honey, and minced garlic. Bring to a simmer. Continue to simmer until sauce reduces and thickens slightly about 5–6 minutes. Once it has reduced, remove the pot from the heat.

After four hours, rinse the fish and pat it dry.

Set grill to 225°F.

Create a long foil "boat" by folding up the sides of the foil. Then place a thin layer of orange slices inside the boat, and top them with the salmon fillet.

Smoke for 90 minutes (or until internal temperature is 145°F).

For the last 30 minutes of smoking time, brush fish down with glaze every ten minutes.