Preheat the oven to 430º F. Use a sift or whisk to thoroughly combine flour, baking powder, sugar, and salt in a mixing bowl. Add flour and diced butter to a food processor or use two forks to cut butter into the flour until the mixture resembles small pebbles. Add very cold buttermilk to the flour and butter mixture and gently combine into a scraggly dough. Empty the dough onto a clean, lightly floured surface and gently (but quickly) pat it into a rectangle (3/4 to 1 inch thick).
To make square biscuits
Use a knife or cake decorating spatula to remove a thin slice from the edges of your rectangle of dough. Cut the rectangle in half lengthwise. Then cut the biscuits to your desired size. They will rise, but the size won’t change much in the oven.
To make round biscuits
Use a biscuit or cookie cutter to make uniform biscuits. Line biscuits onto a baking sheet approximately 1/2“ apart. Brush a little of the remaining buttermilk onto the top of each biscuit. Bake for 20-25 minutes, depending on the size of the biscuits and your preferences.
Notes
If using honey instead of sugar, combine the honey with the buttermilk then add that to the flour to make the dough.
To make these vegan, use vegan butter and make almond "buttermilk" by combining the milk with 1 tablespoon of lemon juice or vinegar and let it sit for 10 minutes or until it thickens.