1. Place the canned pineapple into a sieve over a bowl to drain thoroughly. 2. In a small bowl, combine the graham cracker crumbs and melted margarine; blend well. Press the mixture firmly into an 8-inch square freezer safe dish. 3. In a separate bowl, combine the milk powder, orange juice, lemon juice and egg white. Using a mixer, beat at high speed for about 3 minutes. Add the sugar and continue beating for 3 minutes more. Gently fold in the drained pineapple. 4. Spoon the mixture into the graham cracker crust. Sprinkle the gingersnap crumbs in a decorative pattern; a circle looks especially festive. Cover with foil or plastic wrap; freeze for at least 8 hours. 5. Let stand a few minutes before cutting into serving size portions. Good to make ahead for a cool summer treat. If desired, decorate the top with bits of candied fruit in a decorative pattern, pressing down slightly, then sprinkle the gingersnap crumbs along the outer edge in a circle before freezing.