Preheat your oven to 180°C (350°F).
Line a 9x4-inch loaf tin with baking paper.
In a large mixing bowl, combine:Almond flourCoconut flourBaking powderSaltGround cinnamon Mix well and set aside.
In a separate bowl, beat together the softened butter and sweetener until smooth.
Add the eggs one at a time, mixing after each addition.
Stir in the banana extract and Greek yogurt until fully combined.
Add the wet ingredients to the dry ingredients and stir until a smooth batter forms.
Fold through the dark chocolate chips and chopped walnuts.
Transfer the batter into the prepared loaf tin.
Cover loosely with foil and bake for 45–50 minutes.
Remove the foil during the final 10 minutes of baking to allow the top to become lightly golden.
Allow the banana bread to cool completely in the tin before transferring to a wire rack.
Slice and serve once cooled.