Love Your Leftovers: You can use an ice cube tray to premeasure the remaining pumpkin purée and freeze it to use for your future PSLs. For extra efficiency, add premeasured amounts of brown sugar and pumpkin pie spice to each cube of pumpkin purée and freeze these all together, so you can just pop a frozen spiced pumpkin cube into the pot with soy milk when you want a latte.