Carefully spoon the pumpkin puree and the 1 cup of almond milk into the ice cube trays or silicon molds, and freeze until frozen. Keep the other 1 1/2 cup of non-dairy milk unfrozen for later use.
Transfer the frozen pumpkin puree and almond milk cubes to the blender, and add in 1 cup of the remaining non-dairy milk, along with the protein powder, maple syrup, and pumpkin pie spice.
Pulse, stopping frequently to tamp down the mixture. Keep blending, adding in additional non-dairy milk as necessary, until you have achieved your desired consistency.
Divide the smoothie into bowls, garnish with any toppings you want, and enjoy!