Check the fillet to make sure all of the pin bones have been removed.
Place the fillet, skin side down, in a large plastic or glass container.
Prepare the brine by combining the dark brown sugar and kosher salt with the water.
Pour the brine over the fillet and allow to cure for at least 4 hours in the fridge. (I usually prepare the night before and let the salmon cure overnight). If the brine doesn't cover the entire fillet, double the brine recipe. It's important the entire salmon be submerged in the brine.
Once cured, remove the fillet from the brine and place, skin side down, on a cooling rack. (I like to place a cooling rack with a baking tray underneath to catch any juices that may drip off).
Gently pat the salmon dry and place back in the fridge to dry for at least 2-4 hours. If possible, place fillet directly under a ceiling fan that's on high, to speed up the process. It's important to make sure the fish isn’t kept at room temperature for too long. Ultimately, the fillet needs to develop a pellicle (a shiny skin that seals the fillet and gives the smoke a sticky surface to adhere to.
When fish is ready, put a light coating of oil on salmon to prevent it from sticking to the grates.
Smoke the salmon for about 2 hours at 200 degrees Fahrenheit, basting the fillet with honey or maple syrup every 40 minutes or so, until the salmon reaches an internal temperature of 135-140 degrees Fahrenheit.
Then carefully remove salmon from the smoker.
Serve immediately as a main dish with peppercorns or capers. You can also allow maple or honey smoked salmon to rest and prepare it to be stored for future recipes.