With the rack in the middle position, preheat the oven to 350°F (180°C). Butter a 10 x 4-inch (25 x 10 cm), 6-cup (1.5 litre) loaf pan and line with parchment paper.
In a large bowl, combine the flour, brown sugar, wheat bran, baking powder, baking soda and salt. Set aside.
In another bowl, combine the buttermilk, oil and egg with a whisk. Stir in the dry ingredients until the flour is just moistened. Set aside 1 tbsp of raisins for garnish and add the remaining ones to the batter.
Pour the batter into the loaf pan. Sprinkle with the reserved raisins and bake for 40 minutes or until a toothpick inserted into the centre of the bread comes out clean. Let cool completely before unmoulding.
Cut into slices and serve. The bread will keep for several days at room temperature if well covered with plastic wrap.
You can replace the buttermilk with a mix of equal parts plain yogurt and milk.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.