Combine the coffee base

• In a bowl, combine the instant espresso, brown sugar, sea salt and water.
• Stir until the sugar and espresso are fully dissolved.

Whip until velvety

• Pour in the cold whole milk.
• Whisk vigorously until the mixture becomes thick, frothy and velvety.

Assemble and serve

• Add the marshmallow syrup to a glass filled with ice cubes.
• Pour the whipped coffee over the ice and stir gently before enjoying.