Start by taking your chocolate milk and pouring it into ice cube trays. Spread it out evenly for the best results. Pop these trays into your freezer and let them freeze overnight. It’s the first step to achieving that creamy texture we all love, and the anticipation while waiting is half the fun!

Once your chocolate milk cubes are firm, take about half of them out of the freezer and toss them into your blender. Next, add the heavy cream, sweetened condensed milk, and vanilla extract. If you're opting for that extra chocolate touch, sprinkle in the cocoa powder as well. Blend everything together until you achieve a smooth, creamy consistency. If it's too thick for your liking, don’t hesitate to add more heavy cream until it reaches your preferred texture. For those who like it sweet, feel free to take a quick taste and adjust with a bit more sweetened condensed milk if needed.

Now comes the hard part: enjoying your frosty or not! If you have remaining chocolate milk ice cubes, just keep them in the freezer for your next frosty. You can repeat the process anytime you want to treat yourself again.