Light and Fluffy Biscuits

Adjust oven rack to lower-middle position and preheat to 400°F. Should your kitchen be warmer than 75°F, please see our guide to baking in a hot kitchen before getting started; the specifics are focused on pie dough, but the overall principles are true of biscuits as well. Sift flour into a medium bowl, then add sugar, baking powder, baking soda, and salt; whisk until well combined (this may take up to 1 minute). Add the butter, toss to break up the pieces, and smash each cube flat. Continue smashing and rubbing until the butter has mostly disappeared into a floury mix, although a few larger, Cheerio-sized pieces may remain. This can also be done with 4 or 5 pulses in a food processor, just take care not to overdo it. The prepared mix can be refrigerated up to 3 weeks in an airtight container, then used as directed below. Add yogurt, and stir with a flexible spatula until the flour has been fully absorbed. The dough will seem rather crumbly and dry at first, but keep mixing until it finally comes together (don't worry about over-mixing; until the flour has been fully incorporated, the greater concern is under-mixing). Once the dough forms a rough ball, turn out onto a lightly floured surface. With your bare hands, gently pat the dough into a squarish shape about 1/2 inch thick, then fold in half; repeat twice more for a total of 3 folds, using only enough flour to keep your hands from sticking. Finish by patting the dough to a thickness of 3/4 inch. If needed, dust away any excess flour, then cut into 1 3/4-inch rounds and arrange in a 10-inch cast iron skillet. Gather scraps into a ball, pat and fold a single time, then cut as many more biscuits as you can. The final round of scraps can be gathered and shaped into a single biscuit by hand. Bake until the biscuits are well-risen and golden brown, about 20 minutes. Let the biscuits cool about 5 minutes to help set their crumb, then serve as desired, whether alongside soups and stews or split for shortcake or breakfast sandwiches. Leftovers can be stored up to a week in an airtight container; to serve, split the stale biscuits in half, brush with melted butter, arrange on a baking sheet, and broil until golden brown, then serve with jam.