Strain the raisins from the milk using a fine mesh strainer; discard the raisins.
In a saucepan over medium heat, combine 1 1/2 cups of the homemade condensed milk, Horizon Organic whole milk, pure maple syrup, and arrowroot starch.
Cook the mixture for 6-8 minutes, or until the mixture stars to thicken and almost begins to bubble.
Remove from heat and add in the pure vanilla extract, and stir to combine.
Transfer to a sealable container and store in the fridge until ready to use. Keeps for up to 5 days in the refrigerator.
* You can add whatever flavor you like at this point. Options include hazelnut extract, chocolate extract, maple syrup extract, almond extract, and peppermint extract.