Add the whole milk, heavy whipping cream, milk chocolate chips, cocoa powder, and candy canes to a slow cooker.
Cover and cook on Low for about 2 hours, stirring every 30 minutes, until the chocolate and candy canes are completely melted and the mixture is smooth.
Stir well before serving.
Serve warm with your favorite toppings, such as marshmallows, whipped cream, crushed candy canes, or mini candy canes.
If serving over an extended period, set the slow cooker to Warm and stir every 30–60 minutes to prevent the hot chocolate from scorching on the bottom.
Notes
Store leftover hot chocolate in an airtight container in the refrigerator for up to 4 days.Reheat gently on the stovetop or in the microwave, stirring well before serving.The candy canes add both peppermint flavor and sweetness, so no additional sugar is needed.