Preheat oven to 450°F.
In a large bowl, combine the flour, baking powder, baking soda, salt, and sugar.
2 cups all-purpose flour, 1 Tablespoon baking powder, ¼ teaspoon baking soda, 1 Tablespoon granulated sugar, ¾ teaspoon salt
Using a pastry cutter or food processor, cut the cold butter into the dry ingredients until crumbs about the size of peas form. Make a well in the center and add the buttermilk, then stir with a spatula or fork just until the dough starts to come together.
6 Tablespoons salted butter, 1 cup buttermilk
Turn the dough out onto a lightly floured surface and knead 5 or 6 times. Pat into a rectangle then fold the left third over, then the right side over into an envelope shape. Pat down, turn the dough a quarter turn, and repeat the folding process once more before patting the dough into a 1-inch thick rectangle.
Cut out biscuits using a circle biscuit cutter, pressing straight down without twisting the cutter, then transfer to a parchment-lined baking sheet. Bake for 14-16 minutes until the tops are golden.
Remove the rolls from the oven and brush with the melted butter, if desired.