What is the key flavoring ingredient in a Tall Iced Caramel Flan Latte?

The key flavoring ingredient in a Tall Iced Caramel Flan Latte is flan syrup. This syrup is specifically crafted to capture the rich, creamy, and caramelized flavors associated with traditional flan dessert, which is essential to the drink's overall profile. The combination of this syrup with espresso and the milk creates a deliciously sweet and indulgent beverage that reflects the dessert inspiration behind the drink.

While other flavoring options like pumpkin spice syrup, mocha sauce, and toffee nut syrup add unique tastes to different beverages, they do not align with the flan-inspired flavor profile of this specific latte. Thus, flan syrup is vital in creating the intended taste experience for the Iced Caramel Flan Latte.