Combine all ingredients in a food processor and blend until powdery. Don’t have a food processor? Chop or grate the chocolate until it is as fine as you can get it, and stir it into the remaining ingredients. Mixture keeps in an airtight container at room temperature for up to 2 months. To use: Heat one cup of milk (coconut, almond or others would work here too) in a saucepan over medium heat until steamy. Add 3 tablespoons hot cocoa mix. Whisk over heat for another minute or two, until it begins to simmer and mix is completely dissolved. Pour into mug, top with mini-marshmallows or a dollop of whipped cream.