Probably the most famous of all the Pillsbury Bake Off recipes is the ‘Tunnel of Fudge Cake', which was one of the winners in the 1966 contest. This cake also led to a boom in sales for the Nordic Ware Bundt pan, which then became the most popular and most-sold baking pan in the US. (Ella Helfrich’s cake was actually the second prize winner that year; the grand prize appears to have gone to Mari Petrelli’s Golden Gate Snack Bread, a savory cheese bread.) The original recipe for Tunnel of Fudge used a packaged Double Dutch frosting mix which Pillsbury...