Adjust your oven rack 6 inches from the broiler element and pre-heat the broiler. Make a foil pan out of heavy duty foil (or use two sheets of regular foil). Just crunch up the sides to hold in the glaze. Place it on top of a broiler pan. This makes for easy clean-up! If you don't feel comfortable cooking in foil, you can always do this in a glass dish instead.
Prepare the glaze while the oven is heating. In a small bowl, stir the honey, lime juice, chili powder and cayenne together. Set aside.
Pat the salmon dry with paper towels and season with salt and pepper. Lay the salmon (skin-side down) in a foil pan, spaced about ½-inch apart. Reserve 2 tablespoons of the glaze in a clean bowl for serving, then brush half of the remaining glaze evenly over the salmon.
Broil until all but the very center of the fish has turned from translucent to opaque and flakes away easily, 10 to 12 minutes, brushing the salmon again with the remaining glaze halfway through broiling.
Drizzle the reserved glaze over the salmon and sprinkle with green onions before serving.