Preheat oven to 350 degrees F (175 degrees C) and line 12 muffin cups with paper liners.
Spread Wheat Bran (2 cup) out on a large baking sheet and toast in oven for to 6-8 minutes, turning once. Keep oven on.
While wheat bran is toasting and cooling, cook some of the Raisins (1 cup) and Water (1/2 cup) in a small saucepan over medium heat until soft and the water has been absorbed, about 10 minutes. Puree raisins until smooth.
In a medium bowl, whisk together wheat bran, All-Purpose Flour (1/2 cup), Whole Wheat Flour (1/4 cup), Baking Soda (1 teaspoon), Baking Powder (1 teaspoon), and Salt (1/2 teaspoon). Set aside.
In a large bowl whisk together Vegetable Oil (1/2 cup) and Brown Sugar (1/2 cup). Add whole Egg (1) and white of the other Egg (1) (discard the yolk or save for another recipe). Whisk to combine.
Stir in pureed raisins, Water (3/4 cup), Buttermilk (1/2 cup), and zest and 1/4 cup juice of the Orange (1).
Add dry ingredients and stir just to combine. Stir in Raisins (1/2 cup). Scoop evenly into muffin cups, mounding the batter. When scooping the batter, the muffin cups will be very full.
Bake in preheated oven for approximately 20 minutes, or until a toothpick inserted comes out clean.
Remove and allow to cool for 5 to 7 minutes before removing muffins from tin to cooling rack.