An innovative San Francisco parlor with its own brand of ice cream.. In Short This no-frills ice-cream shop features small tables and plastic chairs. The flavors range from the classics, like vanilla bean and mint chip, to the unusual, such as lychee and green tea. Of special note are the Rocky Road, packed with marshmallows and nuts, and Bear Claw, literally oozing with ribbons of caramel. Double Rainbow also offers a limited selection of simple sandwiches and bagels.