In a large mixing bowl add 2.5 cups all-purpose flour, 2 tablespoons baking powder, 2 teaspoons white sugar, and 1 teaspoon kosher salt and mix with a whisk.
After the butter has been in the freezer for 15 minutes (or more) grate the stick of butter into the mixing bowl with the flour.
Using a dough cutter cut the butter into the flour mixture – it shouldn’t need much as you’ve grated the butter.
Fold 1 cup buttermilk into the flour mixture, until a sticky dough has formed (don’t overmix).
Cut the dough
Empty the dough out onto a lightly floured surface and carefully using your fingers work the dough into a rough rectangle, that’s about 1 inch thick. Fold the dough over onto itself, into thirds (like an envelope). Press out again using fingers to form another rectangle.
Repeat these steps about another 3 times, being careful not to overwork the dough.
Finally, press out the dough into ½ inch thick shape.
Take a 2-1/2 inch biscuit cutter, cut out biscuit circles by pressing straight down and straight back up again (don’t twist).
With the offcuts form another ½ inch shape and cut out more biscuits until there is no dough left.
Bake the biscuits
Place these biscuit dough circles into a lightly greased baking dish (they can touch each other).
Brush the tops of these biscuits, lightly, with butter then add to the oven. Bake for 10-12 minutes.
Remove when golden brown and brush the tops with melted butter again.
Notes
What to do if you don't have buttermilk on handIf you don’t have buttermilk, mixing your own is a great alternative. You can add 2-3 teaspoons of lemon juice or white vinegar to milk. Let it sit until it starts to sour, about 5 minutes.Use cold butter and buttermilk. Don't overmix your dough, this will result in a tough biscuit. We are looking for fluffy biscuits! When cutting, don't twist your cutter.What to do with leftoversStore in an airtight container at room temp for up to 4 days.Freezing instructionsThis recipe can be frozen after baking.Put them on a baking sheet and freeze separately from each other until solid (flash freezing), then put them in a freezer bag and store in the freezer until needed.Warm in the oven until heated through.