In a large bowl, stir together the flour, oat bran, sugar, baking powder(the original recipe also asks for baking soda which I skipped, for some reason I have a great dislike for soda) , salt, ground cinnamon and orange zest.
In another bowl whisk together the lightly beaten egg, honey, vanilla essence,oil, and milk.
Add the wet ingredients to the dry ingredients, and stir just until moistened.Gently stir in the raisins (The batter will be quite thin).
Pour or ladle the batter to fill the muffin cups, and bake in a preheated oven at 400 degrees F (205 degrees C) for 16 to 20 minutes or until a toothpick inserted into the center of a muffin comes out clean.
Remove from oven and place on a wire rack to cool slightly before serving.