Peel the bananas, put them in a bowl and mash with a fork. Whisk in the sugar and eggs, then the coconut (if using), flour and baking powder. Using a small knife, scrape the seeds from the vanilla pod and add to the mixture, then stir in the lime zest, cinnamon, nutmeg and rum.

In a deep pan, heat some oil (filling a pan no more than 1/3 full) over a medium heat until it reaches 180C, or until a cube of bread browns in 30–40 seconds. Make sure the oil doesn’t get too hot and start to smoke. Gently drop tbsps of the batter into the oil and cook for about 2 minutes on each side, turning occasionally, until dark golden all over.

Scoop the fritters out of the oil and drain on paper towels. Sprinkle with icing sugar and serve hot.