Place the coconut milk, pumpkin purée, pumpkin spice blend, pitted Medjool dates, hemp seeds, and ice cubes in a high-powered blender.
Blend at high speed until the mixture develops a completely smooth and creamy texture.
Check that the dates have been thoroughly broken down and evenly distributed throughout the smoothie.
Pour the finished pumpkin smoothie into a serving glass.
Top with whipped cream, if desired, and lightly dust the surface with ground cinnamon before serving.