Preheat oven to 325 degrees.

Grease and flour an 8-cup loaf pan, 9x5x3 inches. Sift together the flour, baking powder, nutmeg and 1/2 tsp salt into a bowl. Cream the butter and sugar together and gradually add the eggs. Add the mashed banana and mix until well combined. Add the sifted flour and mix until smooth.

Pour the mixture into the loaf pan and bake in the upper half of the oven for about 45 minutes, or until the top is colored and the sides are beginning to pull away from the pan. Cover the top of the cake loosely with foil if it starts to darken too quickly. A skewer inserted into the center should come out clean.

Allow to cool for 5 minutes before removing from the pan and cooling on a wire rack. When completely cooled, wrap in plastic wrap until served to keep it moist.

Tip: Optionally, sprinkle a little brown sugar and/or cinnamon on top before baking.