If you don't have any canned pumpkin on hand, or want to avoid making your own purée, feel free to use real pumpkin instead. Backed and steamed or even microwave cooked pumpkins all work wonderfully to make pumpkin spice lattes. You can also use butternut squash to make pumpkin spice latte. Just blend the cooked pumpkin together with some of the milk until smooth; it's much quicker than making puree but gives great results too. I sometimes even blend the pumpkin with the skin, but taking the skin give a smoother and creamier texture.