Preheat the oven to 350°F. Grease a 9-by-5-inch metal loaf pan with the coconut oil and line it with parchment paper.
Combine the bananas, eggs, butter, and almond butter in a food processor or mixing bowl and mix until the ingredients are well blended. Add the coconut flour, baking soda, baking powder, vanilla, and salt and continue to mix until all the ingredients are well combined.
In a double boiler over medium-low heat, mix together the swirl ingredients. Heat, stirring often, until the chocolate has melted.
Pour the bread batter into the prepared pan and spread it out evenly. As soon as you pour the batter, pour the chocolate swirl directly on top and use a knife to swirl the chocolate throughout the loaf pan.
Bake for 45 minutes, or until a toothpick comes out clean when inserted in the middle. Remove from the oven and let cool in the pan on a cooling rack for 15 minutes before serving.