Preheat & prepare. Preheat the oven to 325°F (163°C). Wrap the outside of a 9-inch springform pan in a double layer of heavy-duty aluminum foil, covering all sides up to the rim.
Make the crust. Combine crumbs, melted butter, sugar, and cinnamon. Stir until every crumb is coated. Press firmly into the pan base using the bottom of a glass. Bake for 10 minutes. Cool completely.
Beat the cream cheese. Beat room-temperature cream cheese on medium speed for 2 to 3 minutes until completely smooth — zero lumps.
Add pumpkin & spices. Add both sugars, all spices, and salt. Mix on medium-low until combined. Add pumpkin puree and sour cream. Mix until the batter is a uniform deep orange with no white streaks.
Add the eggs. Switch to low speed. Add eggs one at a time, mixing just until each disappears — approximately 20 seconds each. Stop the mixer the moment the last egg is combined.
Set up the water bath. Pour the filling over the cooled crust. Tap the pan gently 2 to 3 times. Place the foil-wrapped pan in a large roasting pan. Pour hot water in until it reaches halfway up the sides of the springform pan. Transfer carefully to the oven.
Bake. Bake for 60 to 70 minutes — the edges should look set, the center should wobble slightly when nudged. Turn the oven off, prop the door open 1 inch, and leave the cheesecake inside for 1 full hour.
Chill. Remove from the water bath. Run a thin knife around the edge between the filling and pan wall. Refrigerate uncovered for at least 6 hours, or overnight for the best texture and cleanest slices.