Add the milk, coffee, pumpkin, sugar, vanilla extract, and pumpkin pie spice to a 2 quart crock pot. Whisk well to combine.
Add a cinnamon stick, cover, and cook on high for 4 to 6 hours.
Top with whipped cream and extra pumpkin pie spice.
Notes
Adjust the sugar amount for your tastes. This recipe is less sweet than Starbucks (so if you like Starbucks, add 1 to 2 Tablespoons more sugar), but it's quite sweet if you don't usually put sugar in your coffee (only put in 1 to 2 Tablespoons of sugar if you don't usually take sugar in your coffee).