Being from Brooklyn, I have been drinking Egg Creams since I was a little girl. If I wanted one, I walked up the street and asked the guy at the newspaper stand for one and he would make it right in front of my face.

Here is the recipe from The New York Cookbook by Molly O'Neill - the recipe above is close but there is a specific amount of milk to seltzer. Also the important thing is the continue to move that spoon around to build the head at the top of the drink.

DAVID FOX'S CLASSIC BROOKLYN EGG CREAM
Makes 1

1 cup milk
1/4 cup seltzer, must be seltzer NOT tonic water
2 tbsp Fox's U-Bet Syrup (must be this brand to be authentic)

Pour the milk into a 12 oz chilled glass (it must be made from glass, not plastic). Spritz in the seltzer (or pour it) until a white head reaches the top of the glass. Spoon in the syrup with a little wrist action.*

Drink immediately!

* The wrist action is the most important thing - you must mix with a heavy hand. Very quickly to make sure the head stays at the top of the glass.

Risa's comment: I saw a professional make one on tv recently (on a Bobby Flay tv show) - the person making the drink poured in the milk, then the seltzer and then the syrup and he whipped that spoon around quite fast and furious. He said that it is the most important part of the drink, aside from the Fox's U-Bet Syrup. I guess the taste of that syrup is the authentic thing. If you don't care if the drink tastes official and authentic, or you can't get Fox's U-Bet (which is sold in every supermarket in the NY/NJ area as far as I know - it is even in my lousy store nearby) then use Hershey's. Since you've never tasted the real thing, you won't care if it tastes like the real thing, just that it tastes good. It will!

RisaG