Make the chocolate base: In a medium saucepan, heat milk and Meltaways over medium heat until just boiling. Stir often to prevent burning.
Chill: Transfer your hot chocolate mix to the fridge. Let it cool for at least 2 hours—or up to 2 days if you’re prepping ahead.
Assemble: Add 1–2 scoops of ice cream to a tall glass. Pour the chilled chocolate mixture over top. Finish with a generous dollop of whipped cream, marshmallows, or hazelnut sprinkles.
Serve immediately with a spoon or a straw (and don’t forget the napkin)!