Mix the sugar, salt, and black pepper in a shallow bowl. Coat all exposed surfaces of each salmon filet with the sugar mixture.

Heat a small amount of olive oil in a large nonstick skillet over medium heat. Once hot, place the salmon in the skillet skin-side down and cook for about 5 minutes. Spoon or drain off excess oil, liquid, or heavily darkened sugar if needed. Reduce the heat if the oil begins to splatter heavily, and do not raise the heat above medium.

Carefully turn each filet, keeping the skin attached, and cook for another 2-3 minutes. If the filets are thick enough, turn them onto each side and cook each side for another 2-3 minutes.

Preheat the broiler to 450°F (232°C). Sprinkle 1-2 teaspoons of additional sugar-salt mixture over the top of each salmon filet.

Transfer the skillet to the oven and broil for 5-10 minutes, checking periodically so the salmon does not burn. The sugar remaining in the skillet may become very dark, but the tops of the filets should develop a golden-brown crust.

Remove the salmon from the oven and let it cool for a few minutes. Carefully peel away the dark caramelized skin before eating.