For the crust: Preheat oven to 350 degrees F.
Butter a 9-inch springform pan and line the bottom and sides with parchment paper.
Combine the pecans, flour, brown sugar, graham cracker crumbs, butter, and egg yolk together in a large bowl. Press the mixture evenly onto the bottom of the springform pan. Bake for 10 minutes. Set aside to cool.
Turn the oven down to 300 degrees F.
For the filling: Combine the pumpkin, brown sugar, eggs, cinnamon, nutmeg, ginger, and salt in a large mixing bowl. Set aside.
Use an electric mixer to beat the cream cheese, maple syrup, and bourbon until smooth. Combine with the sour cream and pumpkin mixture. Pour over the prebaked crust. Bake for 60 to 70 minutes, or until the center shows little to no movement when the pan is tapped. Set aside to cool.
Increase oven temperature to 350 degrees F.
For the topping: Combine the sour cream, bourbon, and sugar together in a small bowl. Spread over the cooled cheesecake. Bake for 10 minutes. Remove from the oven and let stand for 15 minutes. Refrigerate for 3 hours or until well chilled. Remove from the springform pan and peel away the parchment paper. Slice and serve.