Preheat oven to 400. Grease or paperline 12 muffins cups.
Combine flours, brown sugar, baking powder, cinnamon, baking soda, nutmeg and salt in large bowl. Combine buttermilk, oil and egg in small bowl until blended;stir into flour mixture just until moistened. Spoon evenly into prepared muffin cups.
Bake 25 to 30 minutes or until golden brown and wooden pick inserted in center comes out clean. Remove from pan. Cool on wire rack. Serve warm or cool completely. Store warm or cool completely. Store at room temperature in tightly covered container up to 2 days.