Heat oven to 350 F. Coat a 9- by 5-inch loaf pan with cooking spray. Spoon a little white sugar into the pans, and shake to distribute around the bottom and lower half of the sides of the pan. This will give a lovely crystalled crust to the finished bread.
Mix flour, baking powder, cinnamon, soda, and salt in a large bowl. Beat eggs and sugar in medium-sized bowl. Beat in oil, buttermilk, bananas, and vanilla. Make a well in center of flour mixture. Add egg mixture. Stir just until flour mixture is moistened and batter comes together. Fold in 1/3 cup coconut, nuts, and chocolate. Pour into prepared pan. Sprinkle with remaining coconut. Bake in 350 F oven 1 hour, 10 minutes, until wooden pick inserted in center comes out almost clean. Let cool in pan on rack for 10 minutes. Turn loaf out on rack to cool.