To create a perfect Old-fashioned Chocolate Ice Cream Soda, it takes only three ingredients - ice cream, club soda, and chocolate syrup - and a little finesse!
Drop one scoop of vanilla ice cream into the bottom of a tall soda-style glass (16 to 20 ounces) glass. Pour 2-3 tablespoons of chocolate syrup on top.
Use a long-handled spoon to mash and mix the ice cream and chocolate syrup together, until they have become a sort of chocolate ice cream slurry.
Now comes the tricky part: Using the soda spoon, slowly stir the ice cream-chocolate mixture with one hand, while at the same time very slowly pouring the club soda into the glass with your other hand. Continue adding club soda until the glass is about three-fourths full. (Don’t fill it all the way or it will overflow.) Taste the soda to make sure it’s chocolaty enough for you. (If not, just stir in a little additional chocolate syrup.)
Finish it all off by adding a scoop of ice cream to the soda glass, and then mount a second scoop to the rim, sidecar style.Top it off with one last splash of club soda, pop in a straw and enjoy!