At the heart of most baking failures the flat cake, the metallic-tasting muffin, the cookie that spreads into a puddle is a leavening mistake. Not a wrong ratio of flour to butter. Not an oven that runs hot. The culprit is usually one of two small tins sitting on the same shelf, treated as interchangeable when they are anything but. Baking powder and baking soda are not the … [Read more...] about Baking Powder vs. Baking Soda: Why Swapping Them Ruins Your Recipe