Boil the water on the stove or in the microwave until super hot.
Pour the boiling water into a blender. Add the sugar, powdered milk and butter powder.
Blend until smooth and thick. Scrape down the sides as needed.
Condensed milk is typically thick and syrupy. If your homemade condensed milk is too thick you can add a little more hot water.
Store in an airtight container for up to a week. Mixture will get thicker as it sets in the fridge. It will loosen up when it's brought back to room temperature.