Preheat oven to 400°F. Add all dry ingredients to a large bowl and mix with a wooden spoon. On the stovetop, melt the butter, then pour into a small bowl with the buttermilk. Add egg to buttermilk and butter mixture, and whisk together. Add the wet ingredients to the dry ingredients and mix with a wooden spoon. Consistency should be wet, but firm. Pour the dough into a greased or parchment paper lined loaf pan and sprinkle oats over the top. Back for 50 minutes, then cool on a wire rack.