If you're looking for a dessert that takes an especially long time to make, plum pudding takes the cake. At a minimum you'll spend a few days preparing this fruity, liquor-soaked, cakelike Christmas dessert, but some recipes call for several weeks or even a year-long ripening and soaking process, where the raisins, figs and other dried fruits soak in cognac or brandy. Every few days, you check the fruit mixture and if it starts to dry out, you add more liquor.
After the ripening process is up, you mix the fruit with eggs, breadcrumbs, spices and other extras, put it all in a cake pan, then steam it for six or seven hours. The pudding is sometimes baked again after steaming, then it's either chilled or flambéed before serving. Not time-consuming enough for you? Some recipes also call for drying the pudding for several weeks before re-steaming and serving. Oh, and don't forget to make a batch of hard sauce to accompany it.