In a big bowl, sift together the flour, baking powder, baking soda, salt, and sugar.
Cut in butter and cheese, using pastry blender.
Stir in pepper; refrigerate dough for 30 minutes; meanwhile preheat oven to 400°.
Gently stir buttermilk into chilled dough; gather the mixture into a ball with your hands, and on a well-floured surface, roll or pat the dough into a 12 x 8 inch rectangle, approximately 3/4 inch thick.
Grease a baking sheet; using a large spatula, or a couple of spatulas, transfer the dough to the baking sheet.
Use a dough scraper, baker's bench knife, or a knife to cut dough into 1 1/2 inch squares.
Separate the squares slightly on the baking sheet.
Brush each square with a little buttermilk.
Bake for 15-20 minutes, or until they are very lightly browned.