Preheat the oven to 350 degrees.

Butter just the bottom of a loaf pan.

Whisk together the flour, baking powder, salt, and sugar into a large bowl.

Add the walnuts and mix.

In a separate bowl whisk the egg, then add the butter and milk and whisk together.

Stir in the wet ingredients into the dry ingredients until just combined (don't overmix!).

Pour the batter into the loaf pan and bake for one hour, or until a toothpick poked into the center comes out clean.