Preheat to 350 F. In a bowl, mix together the bananas, eggs, vanilla, coconut milk, and apple cider vinegar until combined; set aside.
2 overripe bananas, 2 eggs, 1 teaspoon vanilla, ⅓ cup coconut milk, 1 tablespoon apple cider vinegar
In a separate bowl, whisk together the almond flour, tapioca flour, baking powder, cinnamon, and sea salt.
2 cups almond flour, ½ cup tapioca flour, 2 teaspoon baking powder, 1 teaspoon cinnamon, ¼ teaspoon sea salt
Slowly fold the flour mixture into the bowl with the bananas until no flour clumps remain; set aside.
Mix together all the filling ingredients (almond flour, coconut sugar, cinnamon, and coconut oil) in a small bowl until coconut oil is incorporated into the mixture; set aside.
⅔ cup almond flour, ½ cup coconut sugar, 1 teaspoon cinnamon, 3 tablespoon coconut oil
Line a loaf pan with parchment paper or grease with oil. Pour ⅓ of the batter into the pan, then sprinkle ⅓ of the filling mixture over top. Repeat 2 more times, alternating batter and filling mixture. With a thin knife, make a couple big swirls in the batter in the form of large ‘S’s.
Bake for 45 - 50 minutes until a knife can be inserted in the middle and come out clean.