Flaky Buttermilk Biscuits

Method

1. Heat the oven to 450°F with a rack in the middle and line a sheet pan with parchment. Grate the frozen butter on the large holes of a box grater and return it to the freezer while you measure the dry ingredients.
2. Whisk the flour, baking powder, baking soda, salt and sugar in a large bowl. Toss in the grated butter with your fingertips until every shred is coated, then pour in the buttermilk and stir with a fork until a shaggy dough forms.
3. Turn the dough onto a floured counter and pat it into a 1-inch-thick rectangle. Fold it in thirds like a letter, turn it a quarter turn, pat out again and repeat the fold three more times, ending with a 1-inch-thick slab.
4. Cut straight down with a floured 2½-inch cutter without twisting, regathering the scraps once. Set the biscuits touching on the pan so they climb, and brush the tops with the melted butter.
5. Bake 14 to 16 minutes, until tall and deep golden on top. Serve within the hour, split and buttered.