Preheat oven to 350 degrees F (175 degrees C). Line a loaf pan with parchment paper, leaving an overhang on 2 sides.
Combine bananas, eggs, almond butter, and butter in a blender; blend until smooth. Add coconut flour, cinnamon, baking soda, baking powder, vanilla extract, and sea salt; mix well.
Place chocolate chips in a microwave-safe bowl. Heat in the microwave for 1 minute; stir. Continue microwaving in 15-second intervals until completely melted, 30 to 45 seconds.
Stir 2 cups of the banana batter into the melted chocolate.
Drop spoonfuls of the chocolate batter into the prepared loaf pan. Cover chocolate batter with some of the banana batter. Drop spoonfuls of chocolate batter in varying spots over the banana batter. Cover with remaining banana batter.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 55 to 60 minutes. Cool in the loaf pan for 10 minutes; lift loaf onto a wire rack. Cool completely before slicing, at least 2 hours.