Preheat oven to 350 degrees Fahrenheit.

Combine graham cracker crumbs, butter, cinnamon and salt, and mix well. Butter the bottom of a nine-inch pan or springform. Press crumb mixture into pan.

Using a stand or hand mixer, beat cream cheese, pumpkin puree, pumpkin pie spice, sugar and vanilla. Add eggs, one at a time. Blend well.

Pour cheese mixture into the crust and bake for one hour. If top starts to brown, cover loosely with parchment paper. Let cool for 10 minutes.

Mix sour cream, sugar and vanilla extract.

Pour over cooled cheesecake and bake for an additional seven minutes. Let cool fully, then refrigerate.

Decorate with whipped cream and chopped Viennese crunch before serving, if desired.