If condensed milk isn’t really your style, you can absolutely use fresh milk or milk alternatives instead; you’ll just want to add in the milk with the water from the start so that all the spices and coffee notes can brew right into the mixture. Similarly, you can use honey as a substitute for sugar so long as you remember to add it while everything is still hot to give it a chance to mix in properly. Another fun addition is to gently place a scoop of vanilla ice cream on top like it’s a root beer float, really bringing all the sweet notes of the brandy and spices together into a delicious summer treat.
One important thing to note is that a version made with condensed milk, instant coffee, and no spices is considered an easy option that’s just as legitimate and authentic as a fully spiced ayis kōpi. If you’re ordering one from a Sri Lankan restaurant, be prepared to be served the simplified variety that, while still delicious, might not be what you were hoping to pair with your meal.