1. Heat oven to 375 degrees F. Coat 12 indents of standard-size muffin tin(s) with nonstick cooking spray. Set aside.
2. In a large bowl, whisk together bran cereal, both types of flour, the baking powder, baking soda, salt and cinnamon. Make a well in the center of the mixture.
3. In a small bowl, whisk together the milk, eggs, sugar and oil. Stir in the grated carrots and raisins. Pour into well of dry ingredients and fold together until all ingredients are moistened. Divide batter among prepared muffin indentations, a scant 1/3 cup in each. Let rest 5 minutes at room temperature.
4. Bake muffins at 375 degrees F for 16 to 18 minutes or until crowned and toothpick comes out clean when inserted in center of muffin. Cool on a wire rack before serving.