Using a food processor, pulse graham crackers until crumbly. Mix in sugar, ground cinnamon and melted butter until crust forms.
Press graham cracker crust into a 9-inch pie dish. Place pie crust in refrigerator.
In a large bowl, add boiling water and gelatin powder. Stir gelatin powder until completely dissolved.Then, add 1/2 cup cold water and 1/2 cup ice cubes, stir until gelatin is slightly thickened. TIP: Let the gelatin mixture sit for a few minutes to thicken slightly before you add the cool whip otherwise it won’t set up.
Add cool whip topping to gelatin mixture and whisk together until light and fluffy. Mix in lemon juice and lemon peel. Refrigerate for 30 minutes or until mixture has thickened.
Add lemon pie filling to pie crust. Refrigerate for up to 6 hours or until firm.