With paper towels, pat the salmon dry. Sprinkle lightly on both sides with salt and pepper.
For easy cleanup, line the air fryer basket with aluminum foil. Preheat the air fryer to 400 degrees F according to the manufacturer’s instructions (for my air fryer, that is 3 minutes).
In a small bowl or larger liquid measuring cup, mix together the brown sugar, Dijon, oil, soy sauce, garlic powder, and ginger (if using). Spoon all over the top of the salmon.
Slide out the air fryer basket and set it on a heatproof surface. Place the fillets in the basket so that they are not touching.
Cook the salmon in the air fryer for 6 to 11 minutes, depending upon their thickness and your model (fillets around 1 inch will need 8 to 9 minutes). Do not overcook or the salmon will be dry. Salmon is done when it registers 145 degrees F on an instant read thermometer (I remove mine a few degrees early, let it rest, then the carryover cooking finishes the job). Check it a few times towards the end to make sure it doesn’t overcook.
Transfer to a serving plate. Enjoy hot, with a sprinkle of additional salt and pepper as desired.
TO STORE: Refrigerate salmon in an airtight storage container for up to 2 days.
TO REHEAT: Gently reheat leftovers in a skillet on the stovetop over medium-low heat until just warmed through.