It's easy to love the Russian honey cake, a dozen wafer-thin layers of spiced cake and honeyed sweet cream frosting that's as addictive as it is delicious. But to our surprise, it was the knishes that kept calling us back to Michelle Polzine's light-filled, copper-accented cafe in Hayes Valley. Knishes aren't the sexiest foods in the world, commonly associated with countries whose national cuisines are decidedly not celebrated, and the versions we've had in the past have lived up to our low expectations. Not these. Polzine's knishes have a crisp, flaky pastry shell encasing savory and smooth mashed potatoes — it's not food we'd call light, exactly, but they certainly didn't sit like a lead weight in our gut either. Which left us with enough brainpower to appreciate the atmosphere of this friendly cafe modeled on those of Vienna, Budapest, and Prague in the early 20th century.