Karin smiles as she shows a baking tray in front of a laptop's screen. | Vienna: Framed by wooden cabinets, Karin Hofbauer holds a stick of butter to her laptop camera and imparts to the novice bakers gathered virtually in her kitchen the secrets of kneading shortcrust dough. "It's a simple recipe, I've made it so many times for friends and family, and it's always a success," the 62-year-old Austrian says before filling the baked apple tart with nuts and vanilla custard.