Pull the espresso and pour it directly over the sauce. Stir for about 20 seconds, until the sauce has fully dissolved and none is left at the bottom.
2 shots espresso
Steam or froth the milk until hot and foamy. Pour the milk into your espresso filled mug.
3/4 cup 2% milk
Top with whipped cream and a dusting of pumpkin pie spice.
Whipped cream, 1/8 teaspoon pumpkin pie spice
Notes
Pumps to tablespoons. Starbucks pours 3 pumps for a tall, 4 for a grande, 5 for a venti, and one pump is about a tablespoon. This sauce is richer than theirs, so 2 tablespoons in a 16 oz mug matches a grande. This is the conversion nobody prints, and it is what makes the recipe adjustable to any size cup you own.
Iced. Stir the sauce into the hot espresso, cool for a minute, then pour over a 16 oz glass of ice with 3/4 cup cold milk.
No sauce on hand. Whisk 1 tablespoon pumpkin purée, 1 tablespoon brown sugar, 1/8 teaspoon pumpkin pie spice and a pinch of salt into the milk. Warm over medium until steaming, about 3 minutes, do not boil. Froth, pour over the espresso, stir in 1/4 teaspoon vanilla.
Milk. 2% is what Starbucks uses. Oat milk is the best non dairy swap, ideally a barista blend so it foams.
Make ahead. The sauce keeps 2 weeks refrigerated and 3 months frozen. The latte is built fresh.