Prep:

Cup of Yum
1. Start heating up the slow cooker, either on high or low heat, to get the bowl warm.
2. In a microwave-safe bowl, heat up 2 cups of milk for 2 minutes until it's hot, not boiling.
3. Combine the powdered cocoa with the hot milk and mix to incorporate, until you have no powdered left.
4. Pour the chocolate mixture into the bowl of the slow cooker and add the sugar. With a whisk, stir to start melting the sugar with the warm chocolate mixture. Pour the rest of the milk and half and half into the slow cooker and combine.

Cook:

1. Cook on low for for 2 to 3 hours or on high for 45 minutes to 1 hour. Add the vanilla at the very end and stir.
2. When it's time to serve it, reduce the heat to the warm setting. If your slow cooker doesn't have a warm setting, reduce it to low and stir occasionally to prevent burning at the bottom of the pot.
3. Optional: Top the slow cooker with marshmallows and a dusting of cocoa powder.

Serve:

1. Laddle out the hot chocolate into mugs and top with marshmallows and a dusting of cocoa powder.