By Kasia Pilat and Alexa Weibel, The New York Times When Lisa Younes visited her local Whole Foods Market in Berkeley, California, last month she expected to walk out with a slice of her beloved Berry Chantilly cake: With its lofty layers of almond-scented cake and fluffy mascarpone frosting dotted with fresh mixed berries, it had become her go-to sweet treat for the past year. But there were none available.