Combine. Add heavy whipping cream (1 1/2 cups), milk (6 cups), sweetened condensed milk (1 can), and vanilla extract (2 teaspoons) to a crockpot, and whisk to combine. Add chocolate chips (11.5-ounce bag) and stir. Cover and cook for 1 1/2 -2 hours on low, stirring occasionally, until chocolate is melted and mixture is hot.
Whisk + enjoy! Whisk well before serving. Ladle into cups and serve with marshmallows. Enjoy!
Notes
Stir before serving. Chocolate can settle slightly as it sits. A quick whisk right before serving ensures every mug is perfectly smooth.
Keep it warm for parties. Once heated, switch the crockpot to WARM. Stir every 30–45 minutes if serving for several hours.
Milk chocolate really matters. Because this recipe already includes cream and condensed milk, milk chocolate gives the best balance. Dark or semisweet can taste too intense for many guests.
Set up a toppings bar. Mini marshmallows, whipped cream, caramel drizzle, crushed candy canes, chocolate shavings, and sprinkles turn this into a fun self-serve station.