Mix the graham cracker crumbs, 1 teaspoon of cinnamon, 3 tablespoons of sugar, and the melted butter together in a bowl, and press the crust mixture into the bottom of a 9-inch pie plate, pressing the crumbs up the side of the plate. Chill until the crust is firm, about 30 minutes.
Pour the water into a bowl, and sprinkle the gelatin over the water. Allow the gelatin to soften in the water for about 5 minutes. Combine the pumpkin, egg yolks, 1/2 cup of sugar, milk, salt, ginger, and 1/4 teaspoon of cinnamon in a saucepan, and mix until smooth. Heat the mixture over medium-low heat until it almost reaches a simmer, and cook until thickened, stirring constantly, about 5 minutes; stir in the gelatin and water until the gelatin is dissolved. Remove the mixture from the heat.
In a separate bowl, beat the egg whites with an electric mixer until they form soft peaks; gradually beat in 1/2 cup of sugar and the vanilla extract until the mixture is glossy. Lightly fold the egg whites into the pumpkin mixture, keeping as much air in the mixture as possible. Scoop the pumpkin mixture into the graham cracker crust. Chill several hours or overnight.
