Add the brown sugar syrup, espresso, cinnamon, and a generous amount of ice to a cocktail shaker or mason jar with a tight-fitting lid.
Shake vigorously until chilled and frothy.
Pour the shaken espresso mixture, including the ice, into a large glass.
Add 4–6 ounces oat milk and set aside.
In a small glass, combine the pumpkin sauce/syrup, 2% milk, and heavy cream.
Froth with a handheld milk frother until thick and creamy.
Pour the pumpkin cream cold foam over the shaken espresso.
Finish with pumpkin pie spice and enjoy!