Sift dry ingredients
Add oil, eggs, and buttermilk to dry ingredients (don't mix too long - just until the dry ingredients get wet)
Add raisin bran
Mix together in a large bowl and fill muffin cups 1/2 - 2/3 full
Bake at 400 degrees for 15 - 20 minutes (The batter will be thick)
Keeps in refrigerator for up to 6 weeks