2 cans of skim sweetened condensed milk
3-3.5 cups of skim milk (depending on how thick and sweet you want it to be)
2 tablespoons of vanilla extract*
*if you wanted to make an almond flavored one, you could add 2 tablespoons of almond extract instead, or 2 tablespoons of cocoa powder to make a chocolate flavored one, or 2 tablespoons of cocoa powder and a tablespoon of either mint or raspberry to end up with chocolate mint or chocolate raspberry flavor, the possibilities are pretty endless
I poured all these ingredients in to a washed out milk container and then just shook it vigorously (cap on obviously) until all the ingredients were combined. If you don't do that, the condensed milk won't mix in and will just sit on the bottom of the container.
This stuff will supposedly keep for 2 weeks. I only made half the recipe and I will be out of it before the week is up I'm sure so I won't be able to test whether or not it really does have that long of a shelf life yet.