How to Make It
Preheat oven to 325°.
Coat a 9 x 5–inch loaf pan with cooking spray. Line the pan with parchment paper, and coat with cooking spray.
Weigh or lightly spoon flours into dry measuring cups, and level with a knife. Combine flours and next 6 ingredients (through salt). Combine buttermilk and egg; add to flour mixture. Stir just until combined.
Spoon the mixture into prepared pan. Bake at 325° for 1 hour and 5 minutes or until a wooden pick inserted in center comes out clean. Invert bread onto a wire rack; cool completely. Remove parchment; slice bread into 12 slices.