Preheat oven to 375 degrees. Cut out a circle of parchment paper and place it on the bottom of a 9" springform pan. Coat the bottom and sides of the pan with nonstick cooking spray.
In a food processor, combine the graham crackers and 1/2 cup pecans until fine. With the motor running, slowly pour the melted butter through the feed tube until mostly combined.
Dump the crust mixture into the springform pan. Using your fingers, press the crust down onto the bottom of the pan and slightly up the sides. Bake 10 minutes.
Once the crust is cooled, spread softened ice cream in an even layer onto the crust. Freeze for at least 1 hour.
Using a hand mixer, beat the heavy cream on high until very stiff, about 8 minutes. Gently fold in the pumpkin puree, sugar, salt, cinnamon, nutmeg and ginger. Spread the pumpkin mixture evenly over the ice cream layer. Cover with plastic wrap and freeze until ready to serve.
Remove the pie from the freezer 10 minutes before serving. Sprinkle the remaining pecans onto the pie and serve.