Fill multiple 2” by 2” ice cube trays with strong coffee or espresso. Allow to freeze overnight (or longer).
Drizzle chocolate syrup around the base and sides of a tall glass.
Remove 2 coffee cubes from freezer tray along with one cup ice cubes. Place in a high sided, wide mouthed, tempered glass or plastic cylinder. Pour hot coffee or espresso over the iced ingredients to start the melting.
With an immersion blender, combine the melting coffee/ice with 1 cup milk or non-dairy creamer, 2 brown sugar cubes and 1-2 ounces of your favorite coffee and/or chocolate liqueur. Blend until slushy.
Pour into chocolaty glass, garnish with whipped cream (optional), and serve with a summer-style straw.
NOTE: If you don’t have an immersion blender (or a container high enough to contain the contents while blending), you can use a traditional blender; it just means more clean-up and less summer relaxation time!