Preheat oven to 350°F (175°C).
Wrap the outside of your springform pan in foil and set aside.
Make the crust:
Mix graham crumbs, sugar, cinnamon, and butter. Press into pan and bake for 8–10 minutes. Let cool slightly.
Prepare the filling:
Beat softened cream cheese until smooth. Add pumpkin, eggs, sour cream, sugar, spices, flour, and vanilla. Mix just until combined.
Pour into crust:
Smooth the top and gently tap to remove air bubbles.
Prepare the water bath:
Place pan into roasting dish and pour hot water halfway up the sides.
Bake for 55–65 minutes.
Center should jiggle slightly. Let cool in oven (door cracked) for 1 hour.
Cool completely on rack, then chill in fridge overnight.
Serve:
Release springform, slice with hot knife, and add optional toppings.