Preheat oven to 350 degrees and place liners in a muffin pan. Set aside.
Prepare flax eggs by whisking together ground flax and water. Set aside to thicken.
In a large bowl whisk together flour, cinnamon, baking soda, baking powder, nutmeg, and salt. Set aside.
In another bowl combine mashed bananas, shredded apple, sugar and oil.
Add flax eggs and mix to thoroughly combine.
Make a well in the center of dry ingredients and pour wet ingredients in. Stir just to combine.
Spoon batter, it will be thick, into prepared muffin pan. Lightly tap pan on counter to level the batter.
Bake for 18-22 minutes or until a toothpick inserted comes out clean.
Cool for a few minutes in the pand and then transfer to a wire rack to cool fully.