Preheat oven to 350F (175C)² (see note).
Prepare graham cracker crust in a 9″ springform but do not bake. Place in refrigerator to chill while you prepare your cheesecake filling.
In a stand mixer (or in a large bowl with a hand-mixer), beat together softened cream cheese and sugars, scraping down the sides with a spatula occasionally to ensure ingredients are mixed well and lump-free.
Add sour cream and stir well, pausing once to scrape down the sides and bottom of the bowl.
Add vanilla extract, pumpkin puree, and pumpkin spice and stir until well-combined.
Add eggs, one at a time, beating until just mixed after each addition (and scraping down the sides after each addition).
Spread cheesecake batter evenly over prepared crust. Transfer pan to a foil lined baking sheet and place in center rack of 350F (175C) oven. Bake for 40 minutes or longer (see note!), until center of cheesecake is almost set (center may jiggle very slightly, edges should be set and may be slightly puffed or very slightly cracked).
Allow pumpkin cheesecake to cool to room temperature and then transfer to refrigerator and chill for 6 hours or overnight.
Before serving, prepare your cinnamon whipped cream.
For the cinnamon whipped cream topping, combine heavy cream, powdered sugar, vanilla extract, and ground cinnamon in a clean medium-sized bowl.
Use an electric mixer to stir on low-speed. Gradually increase speed to high and beat until stiff peaks form. Pipe or dollop whipped cream over chilled cheesecake. Slice, serve, and enjoy!