Add the sweet cream creamer, half and half, and cocoa powder in a crockpot and whisk together until combined. Break the chocolate bars into smaller squares and add them to the slow cooker then cover.

Let cook for 2 ½ hours on low while whisking every 30-45 minutes. I recommend whisking vigorously in order to help break up the chocolate.  

10 minutes before the cook time is done, add the marshmallows.

Pour and serve with any additional desired toppings.