Start by patting the salmon fillets dry with paper towels. Lightly season both sides with kosher salt and black pepper.

To make cleanup easier, line your air fryer basket with aluminum foil. Preheat your air fryer to 400 degrees F as per the manufacturer's guidelines (for my air fryer, this takes about 3 minutes).

In a small bowl or a larger liquid measuring cup, combine the Dijon mustard, brown sugar (or honey), soy sauce, extra virgin olive oil, garlic powder, and ground ginger if using. Mix thoroughly until well blended. Spoon this mixture generously over the top of the salmon fillets.

Carefully slide out the air fryer basket and place it on a heatproof surface. Arrange the salmon fillets in the basket, ensuring they do not touch each other.

Cook the salmon in the air fryer for 6 to 11 minutes, depending on the thickness of the fillets and the specific model of your air fryer. Fillets that are around 1 inch thick typically need about 8 to 9 minutes. Avoid overcooking to prevent the salmon from drying out. The salmon is fully cooked when it reaches an internal temperature of 145 degrees F, measured with an instant-read thermometer. I prefer to remove the salmon a few degrees early and let it rest, allowing the residual heat to finish the cooking process. Check the salmon towards the end of the cooking time to ensure it doesn’t overcook.

Transfer the cooked salmon to a serving plate and enjoy it hot. Add an extra sprinkle of salt and pepper if desired.