1 (14-ounce) can sweetened condensed milk (fat-free or low-fat also works)
1 (7-ounce) jar marshmallow cream
1 cup semi-sweet chocolate chips
Method
Combine all ingredients in your slow cooker and set to low. Stir occasionally, until chocolate chips are melted and the marshmallow cream is combined, about 2 to 3 hours.
Recipe by Kitchen Meets Girl at https://kitchenmeetsgirl.com/slow-cooker-double-hot-chocolate-2/