Mix oil and sugar thoroughly in a VERY LARGE bowl. Add egg substitute, 2 ounces at a time and beat well. Mix together All Bran and 100 percent Bran. Add boiling water. Stir and let cool. Add buttermilk and vanilla to bran mixture. Sift together flour, baking soda, baking powder and salt. Add bran mixture to the creamed mixture, alternating with the flour. Do this in three portions. Stir thoroughly to blend. If storing batter, store in tightly covered container in refrigerator. This will keep up to 3 months. If using stored batter, DO NOT STIR! To bake muffins, fill paper muffin cups 2/3 full. Bake at 350 degrees for 20-25 minutes or until they test done. Dates, nuts, raisins or glaced fruit may be sprinkled on top of batter in bowl when filling muffin cups. This becomes a filling inside the batter as muffin cups are filled. Muffins are very good cold. They also may be re-heated or frozen after baking.