Cut candy into small pieces. Combine gelatin with cold water in a large saucepan. Let soften 5 minutes. Add candy. Heat slowly over very low heat; stirring constantly until candy melts and gelatin dissolves. Remove from heat. Stir in ice cream and orange rind if using. Place mixture over a bowl partially filled with ice and water. Stir occasionally until mixture thickens. Pour mixture into prepared pastry shell. Chill 3 hours or until firm. Garnish with puffs of whipped cream and candied orange peel if you wish.