In a medium bowl, mix graham cracker crumbs, sugar, salt, cinnamon, and melted butter. The mixture should resemble wet sand. Press the mixture into a 9-inch pie dish and bake for 10 minutes. Allow to cool completely, approximately 20 minutes.
Once the crust has cooled, preheat the oven to 350°F.
Put 3 cups of blueberries, the sugar, salt, cornstarch, and water in a saucepan.
Cook over medium-high heat until the mixture comes to a boil, approximately 2 minutes. Once bubbling, cook for an additional 2 minutes.
Take the pan off the heat. Add the butter and lemon juice and stir until the butter has melted.
Let the blueberry mixture cool to room temperature, approximately 1 hour.
Fold in the remaining 3 cups of fresh blueberries into the cooked blueberry mixture.
Pour the blueberry mixture into the cooled graham cracker crust.
Transfer the pie to the fridge and chill for 2 hours.
Serve the pie with some freshly whipped cream or some vanilla ice cream, if desired.