In a medium saucepan over low heat, combine the large marshmallows, pure pumpkin, cinnamon, pumpkin pie spice, and salt. Stir for about 5–7 minutes until most ingredients are melted.

Remove from heat and transfer the mixture into a mixing bowl. Allow it to cool to room temperature for about 30 minutes.

Gently fold the thawed Cool Whip into the cooled pumpkin mixture until it appears lighter and fluffy.

Pour the pumpkin filling into the prepared graham cracker crust and smooth the top.

Cover with a lid and chill in the refrigerator for at least 8 hours, preferably overnight.

Serve by slicing the pie into wedges and consider adding whipped cream on top.