Preheat an oven to 400 degrees. Generously butter twelve 1/2-cup muffin-tin cups.
In a large bowl, combine the eggs, brown sugar, vegetable oil, buttermilk, salt and bran cereal. Using a wooden spoon, mix well. Let rest for at least 10 minutes or up to 1 hour to soften the bran.
In another bowl, stir together the flour and baking soda. Add the flour mixture to the milk mixture, stirring until just combined. Do not overmix. Stir in the raisins.
Spoon the batter into the prepared muffin cups, filling each cup two-thirds full. Bake until golden, about 20 minutes. Do not overcook.
Transfer the pan to a rack and let cool for 15 minutes. Turn out the muffins onto the rack and serve warm or at room temperature.
Wrap any cooled leftover muffins airtight and store at room temperature for up to 2 days.
Recipe reprinted by permission of Weldon Owen. All rights reserved.