I found another super easy recipe:

Put 1/2 cup boiling water into a blender
Add 1 cup of nonfat dry milk.
Add 2/3 cup sugar.
Add 3 tablespoons of melted butter.
Add a few drops of vanilla.
Cover and blend on high speed for 30 seconds or until smooth.
Remove from the blender.
Use in a recipe immediately or store in a covered container in the refrigerator.