Preheat oven to 375 degrees. Line a cookie sheet with parchment paper.
Combine flour, salt, flax seed, and baking soda in a small bowl, whisk with fork and set aside.
Put vegan buttery spread and sugars into a large bowl and beat on medium speed until fluffy and combined.
Add egg, banana, and vanilla; mix until combined.
Add flour mixture; mix until just combined. Stir in oats, chocolate chunks, and nuts (if using).
Drop tablespoons of dough onto cookie sheets. Bake cookies until golden brown about 12 to 13 minutes. Let cool on cookie sheets for 5 minutes, then cool on wire racks.
Notes
Nutrition facts are for one cookie.If you can't have nuts, just leave them out. That's what we do - or occasionally, I will add some pumpkin seeds to the batter. I included them in this recipe because that is the way that I used to make these years ago.If you can't have eggs, just use one flax seed egg replacer. Combine one tablespoon ground flax seed with three tablespoons water and let sit for a few minutes until it thickens. Then add as you would a regular egg.