1. Combine oats and buttermilk in a bowl & let stand while you get everything else ready. 2. Preheat oven to 400F. Combine flours, baking powder, baking soda, salt and brown sugar in another bowl and stir well to blend - make sure brown sugar lumps are broken up. 3. Add egg and melted butter to oat mixture and stir. 4. Add oat mixture all at once to dry ingredients and stir until all ingredients are moistened. 5. Gently fold in blueberries. 6. Fill well-greased muffin cups full. Bake for 15-22 minutes or until top springs back when lightly touched.