Combine brown sugar and oil and egg in a mixing bowl.
In another bowl, mix sour cream, salt, vanilla extract and baking soda. Add this to the mixing bowl and slowly blend in flour. Do not over-mix. Fold in peaches and nuts. Pour into muffin cups and sprinkle with sugar and/or cinnamon. Put a bit of butter on top of each. Sprinkle nuts on top for more nuttier flavor. Bake at 325° F for 30 minutes.Makes 15-20 muffins Source: