Preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper and set aside.
In a large bowl, sift or whisk together the all-purpose flour, salt, baking powder, baking soda, and granulated sugar.
Scatter the cold, cubed butter over the flour mixture.
Use a pastry blender or two forks to cut the butter into the dry ingredients until the butter pieces are about pea-size.
Pour 1 cup buttermilk into the flour and butter mixture and stir gently with a spatula until just combined; the dough will be slightly wet and in lumps.
Turn the dough onto a lightly floured surface and gently bring it together. Pat it into a rectangle about 3/4 inch thick.
Fold the rectangle into thirds (like a letter), rotate so it lies horizontally, and pat into a rectangle again. Repeat the pat-and-fold sequence a total of four times.
After four folds, pat or roll the dough out to about 1/2–3/4 inch thickness. Using a floured 2½-inch biscuit cutter, cut out biscuits and place them on the prepared baking sheet with the edges touching.
Gather and gently rework the scraps as little as possible to cut additional biscuits.
Brush the tops of the biscuits with 1–2 tablespoons buttermilk.
Bake for about 15 minutes, or until the biscuits have puffed and are golden brown on top.
Serve warm.