Preheat oven to 375°F. Grease muffin tin with nonstick spray and set aside.
Mix together the wheat bran and buttermilk in a large bowl and let sit for 10 minutes.
In a separate bowl, beat together the apple sauce, egg, brown sugar, and vanilla until combined.
Add to the bran mixture and mix just until combined.
Sift the flours, baking soda, baking powder, and salt on top of the wet ingredients.
Then stir the flour mixture into the wet ingredients, until just combined.
Add 1/2 cup of batter to 8 greased muffin cups and sprinkle some additional brand on top, if desired.
Bake for 15 to 20 minutes or until a toothpick inserted into the center of a muffin comes out clean.