How to Make It
In a medium saucepan over medium-low heat, whisk together pumpkin puree and pumpkin pie spice, cooking until spices are fully dissolved and the mixture is fragrant, about 2 minutes.
Whisk in sugar and vanilla and cook until the pumpkin mixture has the consistency of a thick syrup, about 2 minutes. Do not boil.
Whisk in milk; cook until heated fully, about 5 minutes. (For a frothy consistency, whisk vigorously, use an immersion blender, or add mixture to blender.)
Pour pumpkin mixture over espresso shot(s) in a tall glass; garnish with whipped cream and cinnamon, if desired. Serve immediately.