01 - Preheat oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Mix crushed graham crackers, melted butter, brown sugar, and cinnamon until combined. Press mixture firmly into the base of the pan. Bake for 10 minutes, then set aside to cool slightly.
03 - In a large mixing bowl, beat cream cheese and sugar until smooth and creamy.
04 - Add pumpkin purée, eggs, sour cream, flour, pumpkin pie spice, vanilla extract, and salt. Beat until just combined, scraping down sides as needed.
05 - Pour filling over cooled crust. Tap pan gently to release air bubbles. Bake for 50 to 60 minutes until edges are set and center is slightly wobbly.
06 - Turn off oven, crack door, and let cheesecake cool for 1 hour. Remove and cool completely at room temperature, then chill at least 4 hours or overnight.
07 - Whip heavy cream, powdered sugar, and vanilla until soft peaks form. Spread or pipe onto chilled cheesecake. Sprinkle with cinnamon to garnish if desired.
08 - Release springform, slice, and serve.