For the ultimate flaky biscuits, we grate the butter so that it’s evenly distributed in the flour mixture, which is key for flakiness. Freezing the butter prior to grating ensures that it stays in individual pieces throughout the mixing and shaping process. Using a higher-protein all-purpose flour (such as King Arthur) provides the right amount of structure for flakiness (rather than fluffiness, which you’d get with a lower-protein flour) without toughness, while buttermilk gives the biscuits tang and sugar lends complexity. To produce the maximum number of layers, we roll out and fold the dough like a letter five times. Cutting the biscuits into squares is easy and avoids any wasted scraps (or tough rerolls). And finally, we learned that letting the dough rest for 30 minutes and trimming away the edges ensures that the biscuits rise up tall and true in the oven.