In a measuring cup, combine instant espresso powder and boiling water. Stir until the granules are dissolved and allow to cool. Transfer to the fridge for 2 hours.
In the jar of a blender, add chilled espresso, milk, Salted Caramel Sauce, and ice cubes. Place the lid and process until liquified.
Taste and adjust if needed by adding powdered sugar; process again.
Drizzle some Salted Caramel Sauce into a tall glass before pouring in espresso mixture.