Preheat the oven to 425 degrees F. In a small bowl mix the oat bran, cornmeal and buttermilk and set aside to soak. In a large bowl, mix together the rest of the dry ingredients. In a third bowl or large glass measuring cup mix together the eggs, oil, honey and orange zest. Add the blueberries to the dry ingredients and gently mix until all the blueberries are coated. Add the soaked bran and corn meal and the wet ingredients to the dry ingredients and gently fold with a spatula until combined.
Lightly butter a muffin pan or line with muffin cups. Spoon mixture evenly into 10 muffin cups (if you want large, domed muffins) or into all 12 muffin cups (for smaller muffins). Sprinkle each with additional golden brown sugar (optional). Bake at 425 degrees F for 10 minutes. Turn the heat down to 375 degrees F and bake for another 15 minutes. Muffins are done when a toothpick poked in the middle comes out clean. Optional: put pan back into the oven and set oven to broil for 2-3 minutes (watch them!) for slightly browner and toasted muffin tops.
If your pan was lined with muffin cups, gently lift each muffin and turn on its side to cool. If your muffin pan was greased, let the muffins cool for at least 30 minutes before removing.