In a large bowl whisk together the condensed milk and the Cool Whip.
Add the chocolate milk and vanilla and continue whisking until combined.
Place the frosty mixture into a freezer-safe container. Cover tightly with a lid or plastic wrap and place in the freezer.
Freeze for 3 hours stirring once every hour, until the frosty has reached the desired consistency.
Spoon into glasses and serve.
Storage:This copycat Frosty can be kept in a covered freezer safe container for up to 1 month. Allow it to sit at room temperature for about 15 minutes so it becomes the proper consistency before stirring and serving.Notes:If you have an ice-cream maker you can use that instead of putting the frosty mixture into the freezer.I used regular 1% chocolate milk but chocolate almond milk will also work in this recipe.If you don’t have a freezer safe container large enough to hold all of the frosty mixture, divide it up into 2 or 3 smaller batches to put in the freezer. Make sure you don’t fill the container to the very top, the mixture will expand a bit as it freezes. If you freeze the frosty mixture in smaller batches the freeze time will be slightly shorter.I have made this using glass and plastic freezer containers. The mixture in the plastic freezes slightly faster than the mixture in the glass container.