Preheat oven to 325 degrees Fahrenheit.
Adjust the top rack to be positioned in the middle of the oven.
Cheesecake Crust:
Lightly coat a 9x13-inch pan with baking spray and set it aside.
Add the "Crust" ingredients to a large bowl and stir until well combined.
Press the mixture into the prepared pan. Using a measuring cup, press the crust and try to line the sides up to the middle of the pan edges.
Refrigerate or freeze for at least 20 minutes.
Cheesecake Batter:
Make sure all the ingredients are at room temperature before you begin.
In the bowl of a stand mixer or in a large bowl using a hand mixer, beat cream cheese and sugar until light and fluffy on medium-low speed.
Add the rest of the ingredients from the "Cheesecake Batter" list and continue beating until well combined and creamy. Scrape the sides and bottom of the bowl with a spatula.
Take the crust out of the freezer and pour half of the cheesecake batter into the prepared pan. Return it to the freezer for about 1 hour, allowing the layer to freeze sufficiently so that you can pour the pumpkin layer on top.
Set aside the remaining half of the cheesecake batter. It will be used for the pumpkin layer.
Pumpkin Layer:
Add the ingredients for the "Pumpkin Layer" to the reserved cheesecake batter, and whisk until fully combined. Use a spatula to scrape the sides and bottom of the bowl.
Remove the cheesecake from the freezer and pour the pumpkin layer on top. Level the top with a spatula.
Bake:
Read the post for "water bath" tips if you want to bake the cheesecake using a "water bath".
Bake in the preheated oven for about one hour.
Do not open the oven door. At the 45-minute mark, check the cheesecake to see if it is done. The center should have a slight wobble, and the edges should be puffed and light golden brown.
Turn off the oven, prop open the door, and let the cheesecake cool in the oven for one hour.
Chill:
After one hour, remove from the oven and place on a cooling rack for about 2 hours, until the cheesecake is cool enough to be transferred to the refrigerator.
Transfer to the refrigerator and chill for 6-24 hours.
Cinnamon Whipped Cream:
Add cream, sugar, vanilla, and cinnamon to a large bowl.
Using a hand mixer or stand mixer, whisk on slow-medium speed, gradually increasing to high speed. Mix until soft peaks form and the whipped cream holds its shape.
Add the whipped cream to a pastry bag, fitted with a star piping tip, and pipe it onto cheesecake bars right before serving.