01 -
Heat 1 cup of whole milk in a microwave-safe container until just scalding. Whisk in ¼ cup of unsweetened cocoa powder until fully incorporated and smooth.
02 -
In a 4-quart or larger slow cooker, add 14 oz sweetened condensed milk, 1 cup whole milk, 1 cup heavy whipping cream, 1 teaspoon vanilla extract, and 1 cup semi-sweet chocolate chips. Stir in the warm cocoa mixture prepared earlier.
03 -
Cover the slow cooker and cook on low heat for approximately 2 hours, stirring vigorously at intervals to ensure the chocolate chips melt evenly and the mixture is smooth and heated through.
04 -
Ladle the hot chocolate into mugs and garnish with mini marshmallows or whipped cream as desired.