Preheat the broiler to very hot.

Cut off the top of the pineapple. Cut a slice off the bottom to stabilize the pineapple, then peel from top to bottom with a sharp knife. Cut out any "eyes" in the fruit. Cut into 1/2 -inch-thick slices. Using a small cookie or biscuit cutter, cut the core out of each slice. Divide the slices on ovenproof plates. Chill until ready to serve. In a small bowl, toss together the macadamia nuts, sugar, butter and salt. Spoon over the pineapple slices. Broil (not too close to the heat) until the topping is caramelized and bubbly, about 2 to 4 minutes. Serve hot.