Divide ¼ cup of chocolate syrup and 1 cup of whole milk into two 16-ounce glasses. While beating vigorously with a fork, slowly pour Vintage Seltzer until each glass is almost full. It will get nice and frothy (though the froth at the top will subside if you don't drink your beverage right away, or if you get heavy handed with the milk). Either will still result in a fizzy, delicious beverage.
Add a straw (optional) and serve very cold.
Recipe by In Good Taste at https://ingoodtaste.kitchen/how-to-make-a-vintage-new-york-egg-cream-bar/