Preheat oven to 350°F. Lightly grease a bread pan.
In a large mixing bowl, whisk together the whole wheat flour, rolled oats, baking soda and brown sugar until evenly combined.
Pour in the melted butter, buttermilk and water. Stir well until a dough forms.
Transfer the dough to the prepared bread pan, spreading it evenly.
Using a sharp knife, score a shallow line down the center of the dough. Sprinkle a few extra oats on top, pressing them gently into the surface.
Bake for 50-55 minutes.
Remove from the oven and let the bread cool in the pan for 5–10 minutes. Then, transfer it to a wire rack to cool completely before slicing and serving.
