First you make a strong coffee and let it cool down.
In a small saucepan, stir the cinnamon, sugar with 100 ml milk and slowly bring the whole thing to a boil while stirring. Take the pot off the stove and let it cool down.
If both are cold, take a slightly taller, narrow bowl and add the cold coffee, the cinnamon milk and the rest of the milk. Mix the whole thing with a hand blender, pour the iced coffee into glasses and serve it with ice cubes and a stick of cinnamon each.
Depending on the size of the cups, the amount is two to four.