01 - Preheat oven to 350°F. Line a 9x5-inch loaf pan with parchment paper or grease thoroughly.
02 - In a large bowl, whisk together almond flour, coconut flour, sweetener, baking powder, baking soda, cinnamon, and salt until well blended.
03 - In a separate bowl, whisk eggs until beaten. Add melted butter, almond milk, vanilla extract, and mashed bananas. Mix until smooth and uniform.
04 - Pour wet ingredients into dry ingredients. Stir gently until just combined, being careful not to overmix the batter.
05 - Fold in chopped nuts or sugar-free chocolate chips if desired, distributing evenly throughout the batter.
06 - Pour batter into prepared loaf pan and smooth the top surface with a spatula for even baking.
07 - Bake for 45 to 55 minutes, or until a toothpick inserted in the center comes out clean and the top is golden brown.
08 - Let cool in pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.