The six-year-long conflict that was World War II colored most aspects of American life. Far from the front lines, its impact reached the kitchen, where a series of mandatory rations left American homes with limited sugar, flour, and animal fat. Recipes for sweet, scrappy cakes abounded in newspapers and baking pamphlets. The cooking guides did double duty of instructing American women on how to make the most of their leaner pantries while also boosting morale. A widely published bedtime tale from 1918, “Uncle Wiggly and the Victory Cake,” which was…