Preheat the oven to 450°F / 230c / 220 fan and line a baking sheet with parchment paper.
Use a whisk to sift together the all purpose flour, baking powder, salt and baking soda in a large mixing bowl.
Cube the butter or shortening then cut it into the dry ingredients using a pastry blender or pulse in a food processor. Cut the butter into the flour mixture until it becomes crumbly and resembles peas.
Mix in 1 cup cold buttermilk, just until the crumbs are thoroughly moistened. Add up to ¼ cup additional buttermilk, if needed. The dough shouldn't be overly wet but, slightly sticky.
Roll or pat out on a lightly floured surface about ¾-1 inch thick. Cut into rounds using a 2-inch cookie cutter dipped in flour. Do not twist the dough with the cutter. Cut the dough, then lift the cookie cutter up. Re-roll any scraps and repeat.
Place biscuits 2 inches apart on the baking sheet. Brush the tops with melted butter or heavy cream.
Bake biscuits at 450°F for 13-15 minutes until lightly golden and puffed. (You can broil at the end of baking to make the tops more golden brown, if desired.)
Brush with melted butter after removing from the oven. Serve immediately.
