Place the milk powder, sugar and butter in a blender jar.
Boil the water and add it to the blender jar. Mix once using a spoon.
Blend for a minute on high until the mixture is creamy. Be careful as it could splash when blending. Start at low speed and then go up to high. Blend for about a minute and then carefully open the lid.
You will notice that the mixture is nice and creamy. That is it! Your condensed milk is ready. Use it right away or store it in an air tight container in the refrigerator.
Always use a clean moisture free spoon when taking out the condensed milk from the jar.
And not to forget, please have your kids or the kid in you lick the condensed milk remaining in the blender jar.