Iced Hot Chocolate

The perfect from-scratch iced hot chocolate is just 3 pantry ingredients and 10 minutes away. Adapted slightly from Paris Sweets (Clarkson Potter, 2002).
—Genius Recipes

Serves 4
3 cups (750 grams) whole milk
1/3 cup (80 grams) water
1/3 cup (65 grams) sugar
6 ounces (175 grams) 88% Super Dark Blend Chocolate Bar, finely chopped

Bring the milk, water, and sugar just to the boil in a medium saucepan. Remove the pan from the heat and whisk in the chocolate. The hot chocolate needs to be blended at this point. At Ladurée, this is done with a hand-held blender (also called an immersion blender). If you have this tool, leave the hot chocolate in the saucepan and whip it with the hand-held blender for 1 minute. If you don't have a hand-held blender, transfer the chocolate to a traditional blender and whip on high speed for 1 minute. (When blending hot liquids, be sure to remove the center insert from the top of the blender, and cover the top with a folded kitchen towel to allow steam to escape.) Pour the chocolate into a container to cool; the cooled chocolate can be reheated or served chilled. (The chocolate can be made up to 2 days ahead and kept tightly covered in the refrigerator.)

Chill the hot chocolate until it is very cold, then stir in 3/4 cup (200 grams) cold milk. Whip the cold chocolate for 1 minute with a hand-held blender (or in a traditional blender). Serve the cold hot chocolate over an ice cube or two.
Keeping: Once blended, the hot chocolate can be cooled and refrigerated in a tightly sealed jar for 2 days; reheat gently, or serve as cold hot chocolate.