NYT Cooking: Blotkake, layered spongecake covered with drifts of whipped cream and fruit, is a dessert that Norwegians are passionate and possessive about. It is a traditional sweet finish for any festive meal, whether a long, dark winter lunch or a long, sunlit summer dinner. “Scandinavians really value lingering and feasting at the table,” said Maren Waxenberg, a Norwegian-American cook who lives in New Y...