In a jug, whisk together the egg, coconut milk and sparkling water until combined.
Sift the cake flour, 2 tablespoons corn flour, baking soda and salt into a bowl. Mix in the brown sugar.
Add the wet ingredients to the dry ingredients and stir to form a smooth, runny batter.
Mix the remaining 4 tablespoons corn flour and the desiccated coconut on a plate.
Dip the banana halves in the batter to coat and then roll in the coconut-corn flour mixture until well coated.
Heat the oil in a deep skillet. Fry the coated bananas on both sides until golden and crunchy, about 3 minutes per side. Drain on paper towels. (If not serving straight away, set on a baking sheet, cover with foil and keep warm in a 200-degree oven.)
Serve with coconut ice cream and toasted coconut flakes.