Combine the chocolate and cream in 1 cup ramekins or small heatproof bowls. Place in the slow cooker and place the lid on the slow cooker.
Cook on LOW for 45 minutes. Ramekins and the slow cooker will be hot; carefully remove from the slow cooker with pot holders.
The ramekins will be full; carefully stir in vanilla extract or whisk mixture until it all blends together into a creamy consistency. Serve immediately.