Preheat oven to 400 degrees. Prepare an 20 cm by 20 cm by 5 cm pan with vegetable oil coating. Sift together all dry ingredients. Combine egg and buttermilk and add to dry ingredients all at once; add oil. Stir (do not beat) just until dry ingredients are moistened. Pour into the prepared pan and bake 25-30 minutes. Cut into 16 2-inch squares. Food Exchanges per serving: 1 STARCH EXCHANGES + half FAT EXCHANGE CHO: 13; PRO: 2g; FAT: 3; CAL: 91; Low-sodium diets: Omit salt