Preheat the oven to 350°F (175°C).
Use parchment paper to line a 9 x 13-inch baking pan, leaving enough overhang to make removal simple.
Crush gingersnap cookies in a food processor or in a zip-top bag with a rolling pin until fine crumbs form.Mix crumbs with melted butter (and salt, if using).
Press the mixture firmly into the bottom of the prepared baking pan to form an even crust.
Bake for 8–10 minutes, then let it cool while preparing the filling.
Cream cheese and sugar are combined in a large mixing basin and beaten until smooth and creamy.
Add the vanilla essence, sour cream, and eggs and stir just until combined.
Divide the cheesecake filling in half.In one half, stir in pumpkin puree and spices (cinnamon, nutmeg, ginger, and cloves).
Spread the plain cheesecake mixture evenly over the cooled crust.
Gently spoon the pumpkin layer on top and smooth it with an offset spatula.
Bake for 45–50 minutes, or until the center is set and doesn’t jiggle when shaken.
Let the bars cool to room temperature on a wire rack, then refrigerate for at least 4 hours, preferably overnight, before slicing.