Optionally, chill your serving glasses in the freezer.
Combine the chilled coffee, one scoop of ice cream, and milk in a blender. Blend until smooth.
Pour into a chilled glass and top with an additional scoop of ice cream.
Garnish as desired and serve immediately.
Notes
If you prefer your drink less diluted but still cold, freeze some of your coffee in ice cube trays and use these instead of regular ice cubes.
Ice cream consistency is important. If the ice cream is too hard to scoop, let it sit at room temperature for a few minutes. A slightly softer ice cream blends more easily and creates a smoother texture in your drink.
Blending technique matters too. Start blending at a lower speed to mix the ingredients without causing too much froth. Increase the speed as the mixture starts to smooth out for a perfectly combined drink.
For an affogato-style twist, place the ice cream in the glass before pouring the blended coffee over it to create a beautiful layering effect.
If you prefer your drink less diluted but still cold, freeze some of your coffee in ice cube trays and use these instead of regular ice cubes.