Chill your glass. Pop a tall glass in the freezer for a few minutes. Cold glasses help keep the bubbles lively.
Fill with ice. Add enough ice to reach the top. Crushed ice works beautifully for a smoother sip.
Add the vanilla syrup. Pour 2 to 3 tablespoons over the ice.
Start with less if you prefer a lightly sweet drink.
Top with bubbles. Slowly pour in the club soda or sparkling water. Pouring gently keeps the fizz from overflowing.
Stir lightly. Give it a quick stir to blend the syrup and soda without knocking out all the carbonation.
Finish with cream. Float the half-and-half or cream over the top, then stir again to create a creamy swirl. Add more cream if you want it richer.
Garnish and serve. Whipped cream or a cherry is optional but fun.
Serve immediately while it’s cold and fizzy.