Another great recipe from Orangette.blogspot.com. Blogger Molly adapted this recipe from the book, HomeBaking: The Artful Mix of Flour and Tradition around the World. My addition/modification is the addition of lime zest.
Preheat the oven to 350 degrees Fahrenheit. Butter a standard-size loaf pan.
In shallow bowl mash the bananas with a fork until it is liquidy but still lumpy. Set the banana mush aside.
In a medium bowl, whisk together the flour, baking soda, nutmeg, and salt. Set aside.
In a large bowl (or the bowl of a stand mixer), beat together the butter and sugar until light and fluffy. Add the vinegar, rum and lime zest and beat to mix well. Add the banana purée and the flour mixture alternately, about 1 cup at a time, beginning with the banana and beating to just incorporate. Use a spatula to fold in any flour that has not been absorbed, and stir in the coconut. Do not overmix.
Scrape the batter – it will be thick – into the prepared pan. Smooth the top, and sprinkle evenly with the demerara sugar. Bake for 50-65 minutes, or until the top is nicely browned and a toothpick inserted in the center comes out clean. Let cool on a wire rack for about 20 minutes; then turn the loaf out of the pan and allow it to cool completely.
This loaf will keep, sealed airtight, for three to four days.