Heat oven to 400°. Line a baking sheet with parchment (or leave ungreased)

Add the flour, baking powder, salt, and sugar to a mixing bowl. Whisk together well.

Add the butter to the flour mixture. Use a pastry cutter or your hands to cut the butter into the flour mixture. You want the mixture to be coarse, and the size of small peas.

Add the buttermilk and stir slightly until combined.

Turn dough onto a lightly floured surface. Knead the dough a few times, but gently, and don't overdo it.

Pat dough to about 1 to 1 1/2" thick.

Use a 2 1/2" biscuit cutter or a drinking glass to cut out the biscuits. Use all of the dough.

Place the biscuits on a parchment lined baking sheet 2" apart.

Bake at 400° for 15-18 minutes, or until they are a light golden brown on top.

Remove from the oven and brush with butter, if desired.

Serve warm.