To make biscuits with milk, substitute whole milk for the buttermilk and omit the baking soda.
Preheat the oven to 425°F. Line a large baking sheet with parchment paper or have ready a 10-inch cast-iron skillet.
Whisk to combine in a large bowl:
Add:
Cut in the butter using a pastry blender or your fingers to work it into the flour until it is in small, flattened pieces and the mixture is crumbly. Stir in:
Stir just until the dough comes together. Transfer the dough to a lightly floured surface, and knead very briefly just to bring the dough together. Pat the dough out into a ¾-inch-thick round. Use a floured biscuit cutter (any size cutter will work) to cut out biscuits as close together as possible. Do not twist the cutter—just push it down into the dough. Transfer the biscuits to the prepared baking sheet or skillet with the sides of the biscuits touching. Brush the tops with:
Bake until golden brown, 15 to 20 minutes.