To set up the cocoa toppings board, start with your largest items first, making little piles of each topping such as large marshmallows, donuts, etc. Then move to medium sized toppings like little cookies or medium sized marshmallows. Finish by filling in the gaps with your smallest toppings like mini marshmallows, chocolate chips and so on. Add more where necessary to fill any spaces and create a look of abundance.
To make the cocoa, combine the unsweetened cocoa, dark chocolate pieces, milk and cream in a large saucepan over medium-low heat. Stir constantly until completely incorporated to ensure the chocolate does not burn. Then, continue to stir frequently.
If using vodka, add one ounce to each mug.
Once the cocoa s steaming hot [about 5-10 minutes], ladle into mugs. Serve with the tray of topping options.