Pumpkin Trifle

In a food processor, combine the graham crackers and candied ginger.
Process until they resemble fine crumbs.
Set aside.
Cut the pound cake into 1-inch-thick slices, then cut each slice into roughly 1-inch cubes.
Arrange about half the cubes in a single layer on the bottom of a glass trifle dish.
Set aside.
In a large bowl, combine 2 cups of heavy cream, 1/4 cup powdered sugar and 1 teaspoon vanilla.
Use an electric mixer with the whisk attachment to beat the cream into stiff peaks.
Spoon about two-thirds of the whipped cream over the cake cubes in the trifle bowl, smoothing it into a single layer with the back of a spoon.
Sprinkle the graham cracker crumb mixture over the cream in an even layer.
To the remaining whipped cream in the bowl, add the pumpkin pie filling, 1/2 cup powdered sugar, pumpkin pie spice, 1/2 cup heavy cream.
Use the electric mixer to beat until thick.
Spoon the pumpkin pie mixture over the crumb layer, then use the back of a spoon to smooth to an even layer.
Arrange the remaining cake cubes in a single layer over the pumpkin pie mixture.
Trifle can be made several hours ahead of time and refrigerated at this point.
Clean the mixer bowl, then combine the remaining 2 cups of heavy cream, 1/2 cup powdered sugar and 1 teaspoon vanilla extract.
Use the mixer to beat to stiff peaks, then spoon the cream over the cake layer.
Decorate the top of the trifle as desired.
Candy corns or orange sprinkles are nice.