Make the crust: in a medium bowl, combine graham cracker crumbs, chopped pecans, gingersnap crumbs, and both sugars, then stir in melted butter. Press carefully into the bottom of a 9-inch springform pan. Freeze for at least 20 minutes.
Make the filling: in a large bowl, whisk together pumpkin, eggs, brown sugar, cinnamon, salt, ginger, nutmeg, and cloves. Add the cubed softened cream cheese and sugar and blend on medium speed with a hand mixer until no lumps remain. Beat in cream, cornstarch, vanilla, and bourbon (if using). Pour into chilled crust.
Bake at 350 degrees for 50-55 minutes or until the center is set. (If your springform pan tends to be leaky like mine, you may want to place a baking sheet underneath it.) Cool in the pan on a wire rack for 5 minutes.
Meanwhile, make the cream topping: in a small bowl, whisk together the sour cream, sugar, and maple syrup. Spread over the top of the baked cheesecake, smoothing with a spatula. Bake another 5-10 minutes, then cool completely. Garnish with pecan halves and store in the refrigerator until ready to serve.
*Tip for serving: instead of a knife, try slicing the cheesecake using dental floss. Way less mess!