1. Preheat oven to 375 degrees.
2. Mix together whole wheat flour, all-purpose flour, baking soda, and baking powder.
3. Stir in the buttermilk and mix until dry ingredients are just moist.
4. Knead the dough on a floured surface for 2 minutes. Shape into a ball.
5. Place dough on a nonstick baking sheet, or on a baking sheet lined with a baking sheet liner. Flatten into a 7-inch round, 1 1/2 inches thick. Cut an X across the loaf.
6. Bake for 40 minutes or until the loaf sounds hollow when the bottom is tapped. Cool on a rack.
7. Cut into 9 wedges.
Variation â–  Add cinnamon, nutmeg, caraway seeds, raisins, apple sauce, chopped apples, or dried apricots in Step 2.