Lightly butter a 9-1/2-inch deep-dish pie plate. Set aside. Put the almonds, sugar, flour, and salt into a food processor. Pulse until the almonds are very finely ground. Transfer the mixture to a large bowl and stir in the graham cracker crumbs. In a small bowl, combine the vanilla with the melted butter. Add to the crumbs and mix well. Add 2 teaspoons of water to the mixture, then rub the dough with your fingers until the texture is uniform. Press the mixture between your fingers. It should clump together without falling apart. (If necessary, rub in another teaspoon of water to make it more clumpy.) Transfer the dough to the pie plate. Press it evenly into the bottom and most of the way up the sides. Refrigerate for 10 minutes.
Preheat the oven to 350°F. Bake the pie shell on the center oven rack for 8 minutes. Transfer to a rack and cool completely.