Preheat the Oven: Heat oven to 350 degrees F (175 degrees C). Line the muffin pan with paper or silicone liners.
Mix Dry Ingredients: Combine almond flour, coconut flour, baking powder, baking soda, salt, and sweetener in a large bowl and mix together.
Combine Wet Ingredients: In a separate bowl, combine eggs, melted butter, almond milk, banana extract, and vanilla extract. Whisk them all together.
Combine and Mix: Add the wet mixture to the dry ingredients and mix well. The batter will be thick but scoopable.
Fill Muffin Cups: Divide batter evenly between muffin liners, filling each about ¾ full.
Bake: Bake for 18-22 minutes, or until a toothpick inserted in the center comes out clean.
Cool and Serve: Let muffins cool in the tin for about 5 minutes, then transfer to a cooling rack . Serve well heated or at room temperature.