Brew 2 cups (500 ml) of strong coffee and let it cool to room temperature.
In a blender, add the cooled coffee, 1 cup (250 ml) of chilled milk, 4 tablespoons of sugar, and 8-10 ice cubes.
Blend the mixture until it becomes frothy and smooth.
Pour the cold coffee into tall glasses, leaving some space at the top.
Top each glass with a dollop of whipped cream or a scoop of vanilla ice cream (optional).
Garnish with a sprinkle of cocoa powder or chocolate shavings (optional) and serve immediately with a straw.