Preheat oven to 350 degrees F.

Lightly oil a 9x9 inch glass pan using a paper towel.

In a medium bowl, combine oats, shredded coconut, raisins, chopped walnuts, ground flax seeds, and cinnamon (if using).

Set the dry ingredients aside.

In a large mixing bowl, mash the ripe bananas.

Add the chopped apple to the mashed bananas.

Combine the dry ingredients with the banana and apple mixture.

Mix with a spoon until everything is well combined.

Press the mixture evenly into the prepared baking pan.

Bake in the preheated oven for 30 minutes.

Remove from the oven and let cool on a wire rack.

Once completely cool, cut into 24 bars.