Preheat oven to 425° F (220° C)

Line a baking sheet with a silicone baking mat or parchment paper.

Whisk flour, baking powder, salt and baking soda together in a large bowl.

Cut butter into flour mixture with a pastry blender until the mixture resembles coarse crumbs, about 5 minutes

Make a well in the center of butter and flour mixture. Pour in 3/4 cup buttermilk. Stir until just combined

turn dough onto floured work surface, pat together into a rectangle

Fold the rectangle in thirds. Turn dough a half turn, gather any crumbs and flatten back into rectangle. Repeat twice more.

Roll dough on a floured surface to about 1/2 inch thick

Cut out 12 biscuits using a 2 1/2 inch round biscuit cutter

Transfer biscuits to baking sheet. Press an indent to top of each biscuit with your thumb

Brush with buttermilk

Bake for 15 minutes or until golden brown.