This “effervescent Jew” is delighted to introduce you to Madame Bubbles!
From May 6th, 2010, in Jweekly.com, “Takin’ it to the streets: Jewish vendors add deli favorites to S.F. mobile food scene“:

San Francisco’s Madame Bubbles was on her way to teach Hebrew school a few weeks ago when a small crowd of curious bystanders gathered around her.
jcover05-07-10Riding her 1950s-style adult tricycle, Madame Bubbles, aka Amelia Nahman, had a large basketful of chocolate syrup, milk and seltzer — for making egg creams, the classic East Coast deli beverage.
Nahman typically serves her nine-ounce egg creams at bar or bat mitzvahs, in municipal parks or on the sidewalk in front of bakeries. But on that particular day she was shlepping her ingredients to Congregation Sha’ar Zahav to whip up some samples for her students.
It seems that the inquisitive passersby had a different idea.
In fact, she ended up selling so many egg creams — made with homemade seltzer and served in compostable potato-starch cups — that she didn’t have enough left for her students. But don’t feel too bad for the kids; they’ll get to taste a real New York egg cream soon enough, at a Sha’ar Zahav picnic in Dolores Park on Saturday, May 8. Nahman has been invited to pedal over and serve up her treats.
Nahman’s egg cream business, named simply “Egg Cream Cart,” is part of an ever-expanding group of specialty food-cart vendors popping up across the nation, primarily in San Francisco, Portland, Los Angeles and New York. Call it a movement if you will, and it’s growing at a “gastronomical” rate thanks to a perfect storm of social networking and an active foodie community…