Brew 60 ml of strong coffee and let it cool down to room temperature.
In a blender, add 250 ml of cold milk, 2 scoops of vanilla ice cream (about 100 grams), the cooled coffee, and 2 teaspoons of sugar (adjust to taste).
Blend the mixture until smooth and frothy.
Pour the coffee milkshake into a tall glass and garnish with a dollop of whipped cream and a sprinkle of cocoa powder or chocolate shavings, if desired.
Serve immediately with a straw.