In a bowl, combine the softened cream cheese, pumpkin puree and sugar.
Beat with a whisk until combined.
Add in the egg, vanilla extract, pumpkin pie spice, sift in hojicha powder and cornstarch and continue to whisk until smooth, being careful not to overwhip.
Once the crust is completely cool, (if using springform pan), line the exterior of the pan with 2 layers of aluminum foil (to prevent water from seeping in).
Pour in the cheesecake filling and gently tap to release any trapped air bubbles.
Reduce oven temperature to 325°F/163°C.
Prepare a water bath by filling a roasting tray with 95°F/35°C to about half of the height of the cheesecake.
Carefully add the cheesecake to the water bath.
Bake at 325°F/163°C for 25 minutes, and then increase to 350°F/177°C for another 15-20 minutes.
The cheesecake should bounce back when lightly tapped with a spoon or silicone spatula.
Turn off the heat and pop the oven door ajar slightly, let the cheesecake cool in the oven for an hour before removing.
Remove cheesecake from water bath, as well as the aluminum foil.
Let the cheesecake cool to room temperature and then lightly cover and place into the fridge for at least 6-8 hours, or overnight to set.
Once set, remove the springform ring, cut into slices and serve with a dollop of whipped cream.