Sift together flour, baking soda, baking powder, and salt.
In a large bowl, cream sugar and butter or margarine. Beat the egg slightly, and mix into the creamed mixture with the bananas. Mix in sifted ingredients until just combined. Stir in milk and nuts. Spread batter into one greased and floured 9x5 inch loaf pan.
Bake at 350 degrees F (175 degrees C) until top is brown and cracks along the top.