Directions

1. Preheat oven to 375 degrees. In a large bowl, whisk together flour, baking powder, baking soda, salt, and sugar. Using a pastry blender, cut in the butter until the mixture resembles coarse crumbs with a few large clumps remaining.
2. Pour in the buttermilk; using a rubber spatula, fold buttermilk into the dough, working in all directions and incorporating crumbs at the bottom of the bowl, until the dough just comes together. The dough will be slightly sticky; do not overmix.
3. Turn out the dough onto a lightly floured work surface. With floured fingers, gently pat the dough into a round about 1 inch thick, pressing in any loose bits. Do not overwork the dough. Use a floured 2 1/4-inch round biscuit cutter to cut out the biscuits as close together as possible. (Use one cut edge as the edge for the next biscuit.)
4. Place the biscuits about 1 1/2 inches apart on an unlined baking sheet. Generously brush the tops of biscuits with buttermilk. Bake, rotating sheet halfway through, until the biscuits are golden and flecked with brown spots, 18 to 20 minutes. Transfer biscuits to a wire rack to cool.