For crust, in a medium bowl, stir together crushed graham crackers, pecans, the 1/4 cup granulated sugar, and the 1/4 cup brown sugar. Stir in the melted butter. Press mixture into the bottom of a 9-inch springform pan.
For filling, in a large bowl, combine cream cheese, the 1/2 cup granulated sugar, the 1/2 cup brown sugar, the pumpkin, eggs, whipping cream, cornstarch, cinnamon, the 1 teaspoon vanilla, the nutmeg, ginger, and salt. Stir in the 1 tablespoon bourbon, if you like. Beat with an electric mixer on low speed just until combined.
Turn into prepared crust. Bake in a 375 degree F oven about 50 minutes or until the center appears nearly set when shaken.
Stir together sour cream, the 2 tablespoons granulated sugar, and the 2 teaspoons vanilla; spread over cheesecake.
Return to oven and bake for 5 minutes more. Cool for 15 minutes in a pan on a wire rack. Loosen side of pan; cool for 30 minutes more. Remove side of pan; cool completely.
Chill in the refrigerator for at least 4 hours. Makes 12 to 16 servings.