Dissolve gelatin mix in boiling water. Stir in salt, then stir in cold water. Chill until slightly thickened, about 30 minutes.

Spray an 8-inch mold with nonstick spray.

Fold cabbage, carrots, and nuts into thickened gelatin. Pour mixture into the prepared mold and chill until firm, 1 1/2 to 3 1/2 more hours.

When ready to unmold, set mold in a sink full of hot water for a few seconds to loosen. Remove from the sink, place a serving plate on top of the mold, and flip over to release salad.