Preheat the oven to 375°F.
Mix the graham cracker crumbs, sugar, and melted butter in a medium bowl until well combined.
Press the crumb mixture into the bottom and up the sides of a 9-inch pie dish, making sure to pack it tightly. Using a measuring cup helps to form a nice even crust.
Bake the crust for 10 minutes, then remove from the oven and let cool.
Whisk together the pumpkin puree, sweetened condensed milk, eggs, cinnamon, ginger, nutmeg, and salt in a large bowl until smooth.
Pour the filling into the cooled crust.
Bake the pie for 45-50 minutes, or until the filling is set and a toothpick inserted in the center comes out clean. You may want to cover the crust with foil or a pie shield to prevent it from burning.
Let the pie cool to room temperature before serving.
Serve with whipped cream, if desired.