"Why this recipe works:For our Sweet Potato Biscuits recipe, we started with a traditional biscuit recipe and slowly traded buttermilk for sweet potato until we discovered we didn’t need any buttermilk at all. A dash of cider vinegar made up for the buttermilk tang and also lightened up the biscuits. We tried incorporating the sweet potatoes raw, boiled, baked, and from a can before we settled on an extended stay in the microwave. This concentrated their flavor and released most of their moisture. All-purpose flour yielded biscuits that were a little too tough. We found biscuits made with cake flour to be far more tender...."