If you have it, skim milk powder or coffee creamer will make it even more flavorful
Combine the ingredients in a large, heatproof bowl, and heat in the microwave at 500-600 W for 1-2 minutes. Remove from the microwave and mix. Repeat this process 2-3 times.
When it looks like this when removed from the microwave, it's ready. Chill (or let cool, then chill) and it's done.
If you continue heating it, it will brown and become a caramel sauce.
Note: Because it may boil over, I recommend you use a large heatproof bowl.
Story Behind this Recipe
When making shaved ice, an easy topping is condensed milk, but it's so expensive that I decided to make my own.
Please adjust the heating time according to the amount and your container. Once it looks like the picture in Step 2, it's ready. Once finished, it doesn't seem like it will be thick, but once chilled, it will thicken, so don't worry.