You can count on almost one hand how many places there are left in New York where you can get an egg cream, but once upon a time they were available on nearly every block. One of the staples of the classic soda fountains that became the city's gathering places during Prohibition, the egg cream is a uniquely New York creation whose origins are wildly debated.
Chocolate Egg Cream
Recipe by Daniel Humm and Will Guidara
1 cup sugar
3 ounces Mast Brothers Madagascar chocolate, chopped
6 tablespoons cocoa powder
2 tablespoons cornstarch
In a small saucepan over medium heat, melt together the sugar and chocolate with 1/3 cup of water. In a mixing bowl, whisk together the cocoa powder and cornstarch with 1/3 cup of water. Add to the melted chocolate mixture and bring to a boil. Cook for 2 minutes to cook out the starch. Strain through a chinois and chill over an ice bath. Refrigerate until ready to use. Note: Any leftover chocolate sauce can be stored in the refrigerator for up to 1 week and used to make hot chocolate or chocolate milk.
3/4 cup milk
Pour 3 tablespoons of chocolate sauce into each of four 8-ounce glasses. Top with 3 tablespoons of milk. Add enough seltzer to almost reach the top of the glass. Stir vigorously and drink immediately.