Make the pumpkin pie mix: In a medium saucepan, whisk together the heavy cream, sugar, cinnamon and pumpkin pie spice mix until combined. Bring to a simmer over medium heat, stirring with a wooden spoon, 2-3 minutes. Transfer to a storage container. Refrigerate.

Make the lattes: In a small saucepan, heat the milk, whisking as it heats, until it simmers and becomes foamy. (Alternatively, microwave milk until hot and whisk). Divide the hot coffee between two cups, stirring in 3-4 heaping tablespoons of the pumpkin mix until smooth. Pour half of the milk over each.