Measure out all items and keep on your work surface where you can see them.
Pour your milk powder into your sugar bowl.
Add in your softened unsalted butter and vanilla extract (if using).
Next, add in your boiling water. Be careful not to hurt yourself. Then whisk all well together for 5 minutes.
Allow your Sweetened Condensed Milk to cool. It will thicken slightly but still have that running consistency.
Use immediately or pour into a sterilized jar and refrigerate for up to 2 weeks. Enjoy!
ALTERNATIVELY, You can add all items into a blender and blend all together for 5 minutes. And you got yourself a rich, delicious, and creamy condensed milk without stressing yourself! If too thick, thin with ½ tbsp of warm milk at a time till you get desired consistency.