Sweetened Condensed Milk. 1 cup sugar 1 cup dry powdered milk 1/2 cup water 1 Tbsp butter Put sugar & powdered milk in a blender (I LOVE using my Ninja for this.) Put water & butter in a microwaveable dish & let it come to a boil in your microwave; about 45-60 seconds. Keep an eye on it. Add water/butter mixture to mixer & blend until combined. Scrape sides if you need to & blend again.