Orange-Glow Chiffon Layer Cake

I had given up trying to bake my favorite orange chiffon cake, which depended on the support of a tube pan, as a 9-inch round layer cake until Nushera Tazrin, a lovely and creative blogger from Australia, inspired Woody and me to return to the test kitchen. There, we discovered that using unbleached all-purpose flour and an ungreased, unlined springform pan changed everything. The unbleached flour provides just the right extra support and a properly sized springform pan allows the batter to