Preheat the oven to 450° F (232° C) and add all the dry ingredients to a large bowl. Lightly whisk with a fork to mix.
Add the cold butter and cut it in with your fingers (rubbing and smushing the butter into the flour) or use a pastry cutter until no larger lumps of butter remain, or the butter pieces are around the size of lentils.
Pour the milk over the ingredients in the bowl and stir with a fork. The dough will become lumpy and will not hold together.
Lightly flour a work surface and turn the contents of the bowl onto it. Keeping your hands off the dough as much as possible to avoid warming the butter, bring the dough together to form a ball and gently knead about 10-15 times.
For round biscuits:
Flatten the dough to about 1/2”-3/4” thick and cut with a 2 1/2” round cutter or a glass. Bring any remaining scraps together and repeat. Place the circles on a cookie sheet, ungreased, either touching slightly for softer sides or apart for crunchier sides.
For triangles:
Chop the dough ball in half and flatten each half to about 6” in diameter. With a large knife or a pastry scraper, slice each of the dough rounds into 6 slices. Set the triangles on an ungreased cookie sheet, either touching slightly for softer sides or apart for crunchier sides.
Bake for 12-14 minutes or until lightly golden.
To cool:
Place a clean kitchen towel on a cooling rack and remove the biscuits from the cookie sheet to the towel. Cover and cool for about 30 minutes to develop the most flavor.
Note: If you replace the milk with buttermilk (or yogurt), reduce the baking powder to only 2 teaspoons plus add 1/4 teaspoon baking soda.
Variation: Exchange one of the cups of all-purpose flour with 1 cup of oat flour (regular oats ground to a powder).
Notes
Adapted from Elizabeth Alston’s Biscuits and Scones cookbook.