How to Make It
Drain pineapple well; reserve juice.
Combine reserved juice with pineapple juice in measuring cup. Add water to make 2 cups.
Combine juice mixture and gelatin in saucepan. Let stand 1 minute. Stir over low heat until completely dissolved. Stir in sweetener.
Pour into bowl. Chill until slightly thickened (consistency of egg whites) about 1 hour.
Fold in pineapple, pumpkin and whipped topping. Pour into graham cracker crust. Chill 5 hours or overnight.
Serve with whipped topping and ground cinnamon, if desired.