In a large bowl combine flax seed and water and let rest for 5 minutes to achieve "eggy" texture.
Mash in the bananas until well combined, and then add peanut butter, baking powder, baking soda, melted coconut oil, agave nectar, salt, vanilla and stir.
Add oats, almond meal and oat flour and mix well.
Add chocolate chips and walnuts and stir until well combined. Refrigerate for 5 minutes to harden.
Drop cookies by spoonfuls on a lightly greased baking sheet - they won't expand much. Also make them as uniform in size as possible to ensure even baking.
Bake for 15-17 minutes or until the cookies are slightly golden brown.
Let rest on baking sheet for a few minutes before transferring to a cooling rack. After completely cooled, store in an air-tight container to keep fresh for up to a few days. Refrigerate or freeze for even longer storage time.