Place all ingredients into a high speed blender. (Since you're blending a hot liquid, you may have to do this in smaller amounts, and start slow to avoid blender blunder. I remove the center insert to let the steam escape and place a kitchen towel over the insert, holding down the lid, while blending. Or you can use an immersion blender.)
Blend for about a minute or less (blending for more will result in a gelatinous texture)
When done blending, pour the liquid through a fine mesh strainer and allow the hot chocolate to drain through
Pour into individual cups. Top with whipped cream, marshmallows, or any other desired toppings.