Fill a medium sauce pan ¼ of the way with water and heat over a medium-high flame. When the water starts to boil, lower the heat to a simmer and place a glass bowl over the pan, making sure it doesn't touch the water. Add the chocolate chunks, coconut oil, and butter. Stir using a rubber spatula until the chocolate has melted. Remove the bowl from the heat and add the cinnamon. Stir well and set aside.
Preheat the oven to 350 degrees.
In a large bowl, mash the bananas using a fork. Sift the coconut flour, salt, and baking soda into the mashed bananas. Using a rubber spatula, lightly fold the sifted flour mixture into the bananas.
In a medium bowl, add the almond butter and eggs. Use a fork or whisk to combine until creamy. Add the mixture to the dry banana mixture and combine well.
Brush a loaf pan with coconut oil. Add ½ of the banana mixture into the loaf pan. Next, add in 2 tablespoons of the melted chocolate mixture and use a fork to swirl the mixture. Add the remaining banana mixture to the top and then repeat with the chocolate and swirling. Bake in the oven until cooked through, about 50 minutes, and enjoy warm.