In a cocktail shaker, combine all the ingredients. Cover and shake for 15 to 20 seconds.
Fill the shake a quarter full with ice and shake for 3 to 5 minutes. Really give your biceps a workout and shake that bad boy as hard as you can (preferably with two hands). It's important to create a creamy consistency.
Pour into a chilled Collins glass and top with soda until foamy head forms.