In a mixing bowl, whisk together the French vanilla instant pudding and pumpkin pie spice until thoroughly combined, about 1 minute.

Pour in the heavy cream and add the pure pumpkin to the dry mixture. Blend using an electric mixer on medium speed for 1-2 minutes until smooth.

Gently transfer the mixture into the ready-made graham cracker crust and smooth the top with a spatula.

Cover the pie and refrigerate for at least 8 hours, ideally overnight, to allow flavors to meld.

When ready to serve, remove from the fridge, peel off the lid, and optionally garnish with whipped cream.