Preheat the oven to 400°F. Cut the salmon into bite-size pieces and place in a large bowl. Combine the brown sugar, salt, pepper, garlic, paprika, and cayenne in a small bowl and stir to combine.
Lightly spray or drizzle the salmon with olive oil. Sprinkle the salmon with about ⅔ of the sugar and spice mixture and toss with your hands to coat. Spray a large baking sheet with oil and spread the salmon across the baking sheet. Sprinkle each piece of salmon with the remaining spice mixture.
Place the salmon in the oven and bake for 5 minutes. Remove from the oven, and increase the heat to BROIL on high. When the oven reaches broiling temperature, return the salmon to the oven and broil for 3-4 minutes, until the salmon is cooked through and the glaze has lightly caramelized.
Remove from the oven and test the salmon for doneness. The fish should barely flake apart with a fork. The cooking time required will depend on the thickness of the salmon.
Notes
When cooking fish, it's always a good idea to cook it a couple of minutes less than your estimated time, then check for doneness. You can always pop it back in the air fryer or oven, but you can’t fix an overcooked piece of fish.
The most important thing to remember is that the fish will continue to cook for a few minutes after it is off the heat, so you have to remove it just before it is done to your liking. Salmon is best warm and flaking, but still a bit translucent even after resting.