In a medium saucepan place the pineapple pur�e and the heavy cream, and stir them together. Heat the mixture on medium for 8 to 10 minutes, or until it is reduced to a syrup. Keep it warm. In a small bowl place the egg yolks and the cornstarch, and beat them together. Add the egg yolks to the cream mixture. While whipping constantly, cook the mixture for 6 to 8 minutes, or until it is the consistency of a medium whipped cream. Set it aside. In a small bowl place the egg whites. Beat them with an electric mixer on low speed for 2 to 3 minutes, or until they are frothy. Turn the electric mixer on high, and while continuing to beat the egg whites slowly pour the sugar-water mixture down the side of the bowl. Continue to beat the mixture for 8 to 10 minutes more, or until the meringue is very shiny and the bottom of the mixing bowl is cool. Add the cream mixture to the meringue, and gently fold it in. Preheat the oven to 400�F. In each of 4 small souffl� dishes place the mixture so that the dishes are half-filled. Add the shredded coconut. Fill the dishes up with the remaining mixture. Sprinkle the powdered sugar on top. Bake the mousse for 8 to 10 minutes, or until it is set. Remove it from the oven. Place the mousse under a preheated broiler for 30 seconds, or until the sugar is caramelized.