Preheat the oven to 425°F. Whisk the flour, baking powder, soda, sugar, and salt together in a bowl. Drop in the butter and rub it into the flour until you've got crumbs-some the size of flakes, some like baby peas. Add the buttermilk and stir; it will be very sticky.

Reach into the bowl and knead the dough gently 3 or 4 times. Turn it onto a floured surface and roll or pat it into a circle about 1/2 -inch thick. Use a 2-inch biscuit cutter to cut out as many biscuits as you can; gather the scraps, reroll, and cut out more biscuits.

Transfer the biscuits to a foil-lined baking sheet and bake 15 to 18 minutes. Cool for 5 minutes. Serve split, spread with jam or drenched with gravy.