MIX condensed milk, cinnamon, ginger, salt and nutmeg with wire whisk until well blended; set aside.

SPRINKLE gelatine over water in medium saucepan; let stand 1 minute. Cook on low heat 2 minutes or until gelatine is completely dissolved, stirring constantly. Add milk mixture; stir until well blended. Continue cooking 5 minutes or until slightly thickened. Remove from heat. Stir in pumpkin. Spoon into crust.

REFRIGERATE 4 hours or until firm. Top each serving with a dollop of the whipped topping just before serving. Store leftover pie in refrigerator.