- With the rack in the middle position, preheat the oven to 350°F (180°C). Generously butter and flour four small 6 x 3-inch (15 x 7.5 cm) loaf pans.
- In a bowl, combine the flour, baking powder and baking soda. Set aside.
- In another bowl, combine the bananas, coconut milk, 3 tsp of the espresso powder and lemon juice.
- In a third bowl, cream the butter and sugar together with an electric mixer. Add one egg and one yolk. Set aside the egg white for the frosting. Cream until the mixture is well combined. On low speed, add the dry ingredients alternately with the banana mixture. Transfer the batter to the loaf pans.
- Bake for 40 minutes or until a toothpick inserted into the centre of the cakes comes out clean. Let cool completely on a wire rack. Unmould.
- In another bowl, whisk together the egg white, remaining espresso powder and icing sugar. Frost the cakes, as desired.
Exposing bananas to air accelerates the ripening process, so seal the stem of the bunch with plastic wrap to limit oxygen. This will keep them fresh for an extra week.