1. Preheat the oven to 350F (180C). Line a 12-cup muffin tin (with 1/2-cup indentations) with paper liners.
2. Spread the wheat bran on a baking sheet and toast in the oven for six to eight minutes, stirring a few times so it cooks evenly. Let cool.
3. While the bran is toasting, heat 1 cup (135g) of the raisins with 1/2 cup (120ml) of the water. Simmer for ten minutes, or until the water is all absorbed. Puree the raisins in a food processor or blender until smooth.
4. In a large bowl, mix together the toasted bran, buttermilk or yogurt, 1 cup (250ml) water, then mix in the raisin puree, orange zest, and brown sugar.
5. Stir in the oil, egg and egg white.
6. Mix together the flours, baking powder, baking soda, and salt, and sift directly into the wet ingredients. Stir until the ingredients are just combined, then mix in the remaining 1/2 cup (55g) raisins.
7. Spoon the batter into the muffin tins, making sure the batter is mounded slightly in each one. Because muffin tins can very in size, if your tins are larger, make fewer muffins.
8. Bake for 25 to 30 minutes, or until the muffins feel set in the center.