For the crust:
6 ounces gingersnap cookies, finely ground to make 2-1/2 cups
4 to 5 ounces walnuts, finely ground, to make 3/4 cup
1/4 cup granulated sugar
4 to 5 tablespoons butter, melted
For the filling:
Two 8-ounce packages cream cheese at room temperature
3/4 cup firmly packed brown sugar
3-1/3 cups homemade or canned pumpkin purée
1/2 cup heavy cream
1/2 teaspoon freshly ground mace
1/2 teaspoon freshly ground ginger
1/2 teaspoon freshly grated nutmeg
1 teaspoon freshly ground cinnamon
Preheat the oven to 325 degrees F. In a small bowl, mix the ground cookies, walnuts, granulated sugar, and melted butter. Press the mixture over the bottom of a 9-by-2-1/2-inch round springform pan. Using your fingertips, push all but a thin coating of the cookie mixture toward the sides of the pan. Pressing with your fingers, make a crust about 1-1/2 inches up the sides of the pan; the edges will be slightly irregular.
Bake until lightly browned, about 15 minutes. Let cool thoroughly in the refrigerator before filling.
To make the filling: In a large bowl, using an electric mixer, beat the cream cheese and brown sugar together until well blended. Beat in the eggs, one at a time, until the mixture is smooth and uniform.
In a medium bowl, use a spoon to mix the pumpkin purée, cream, and spices together until well blended. Add the pumpkin mixture to the cream cheese mixture, mixing until well blended. Pour the filling into the crust and bake for about 50 minutes, or until the center barely moves when jiggled.
Let cool on a wire rack, then refrigerate at least overnight before serving. To serve, run a knife around the edge of the pan, then release the sides, leaving the bottom of the pan in place. Serve chilled. Serves 12.