Grease and flour 8 nonstick rectangle carbon steel muffin pan (5.5*9cm) or 8*5 inch loaf pan.
Preheat the oven at 170oC.
Mix dry ingredients: flours, baking soda and salt.
In a large bowl mix wet ingredients: egg, sugar, rum, melted butter, oil, banana, condensed milk, until combined. Combine the dry into the wet, 1/3 at a time, being careful not to over mix! (Or you will have tough bread!)
Bake for 40- 45 minutes or until a toothpick comes out clean. If bread starts to brown too much on the top, cover with foil and continue to bake until cooked through.
Cool on rack.
Slice into thick slices and serve.
Note: You can add 40g of bittersweet chocolate, and 40g of Pecans or Walnuts after mixing flour for another choice.
