01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Whisk together flour, baking powder, baking soda, salt, and sugar in a large mixing bowl.
03 - Add cold butter cubes to the flour mixture. Using a pastry cutter or fingertips, blend until coarse crumbs form with pea-sized butter flakes remaining.
04 - Make a well in the center. Pour in cold buttermilk and gently mix until barely combined, avoiding overmixing.
05 - Transfer dough to a lightly floured surface. Pat into a rectangle approximately 3/4 inch thick; fold in half, gently pat out, and repeat folding and patting twice more for enhanced flakiness.
06 - Cut biscuits using a 2 1/2-inch cutter. Arrange on the prepared sheet, placing close for soft edges or spaced apart for crisp sides.
07 - Gently gather and flatten the scraps to shape additional biscuits.
08 - Lightly brush tops with extra buttermilk.
09 - Bake for 16 to 18 minutes until golden brown and risen.
10 - Blend softened butter, finely chopped sage, and salt in a small bowl until thoroughly combined.
11 - Present biscuits warm accompanied by generous portions of sage butter.