1. Heat oven to 400 degrees F. Grease twelve 3-inch muffin cups or line with paper liners. In large bowl, combine both flours, cinnamon, baking powder, baking soda, and salt. In medium bowl, beat buttermilk, oat bran, brown sugar, oil, and egg until blended. Stir buttermilk mixture into flour mixture just until combined. Fold in apples.
2. Divide batter among muffin cups. Bake 18 to 20 minutes or until wooden pick inserted in centers comes out clean. Cool muffins in pan 5 minutes; remove from pan and cool on wire rack.