Heat the milk until simmering and pour into a small mixing bowl.
Using a milk frother or a wire whisk, whip the hot milk until frothy.
Place the dulce de leche in a microwave-safe cup and heat on HIGH for about 30 seconds or just until thin and slightly pourable. Reserve a little of the dulce de leche for the topping.
Add the hot coffee to the rest and stir to combine. Divide between two cups or glasses.
Pour the milk into the glasses, dividing it equally. Spoon the foam on top, again dividing it equally.
Drizzle the reserved dulce de leche on the milk foam.
Serve at once.