Preheat the oven to 350ºF. Line a large baking sheet with parchment paper.
In a large bowl, mix together the flour, oats, ground flaxseeds, cinnamon, baking powder, baking soda, and salt.
In a medium bowl, add the mashed banana, egg, honey, coconut oil, and vanilla. Stir until combined.
Add the wet ingredients to the bowl with the dry ingredients and mix until incorporated. Fold in the chia seeds along with the dried fruit and nuts of your choice. The dough will be thick.
Scoop ¼ cup of dough and drop it onto the prepared baking sheet. Gently flatten the cookies to about 3 inches wide (they will not spread much during baking). Bake until golden brown and set, 13 to 15 minutes.
Remove from the oven and let cool on the baking sheet for 10 minutes. Transfer to a wire rack to cool completely.
Store in an airtight container at room temperature for several days, or freeze in a zipper bag.
Melt the coconut oil first then measure out the correct amount, otherwise you may use too much.