01 - Preheat oven to 325°F. Generously grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine crushed graham crackers, melted butter, brown sugar, and cinnamon in a mixing bowl. Press the mixture firmly into the base of the prepared pan. Bake for 10 minutes, then set aside to cool slightly.
03 - Using an electric mixer, beat cream cheese and sugar in a large mixing bowl 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 the sides of the bowl as needed.
05 - Pour the filling over the cooled crust. Tap the pan gently on the counter to release any trapped air bubbles. Bake for 50-60 minutes, until the edges are set and the center remains slightly wobbly.
06 - Turn off the oven and crack the door open. Allow the cheesecake to cool gradually inside for 1 hour. Remove from oven and cool completely at room temperature, then refrigerate for at least 4 hours or overnight.
07 - Whip the heavy cream, powdered sugar, and vanilla extract until soft peaks form. Spread or pipe the whipped cream onto the chilled cheesecake. Sprinkle with ground cinnamon for garnish if desired.
08 - Release the springform pan ring, slice the cheesecake, and serve chilled.