Add all of the ingredients in the crockpot, whisking to combine.
Cook on high for an hour or on low for 2 hours, stirring occasionally, until chocolate is completely melted, and the hot chocolate is heated through.
Switch the crockpot to low or the keep warm setting, do not keep it on high or it will burn. Stir often at your party.
Ladle the hot chocolate into mugs/cups and serve with mini marshmallows.
Notes
When making this easy crockpot hot chocolate, you can use mini chocolate chips, Hershey's melted chocolate bars, dark chocolate morsels, or even white chocolate chips. Use whatever chocolate you have on hand.
To reheat: Warm hot cocoa in a microwave safe bowl for 20-second increments until your desired warmth is reached.