Preheat oven to 350 degrees F. Line a baking sheet with parchment paper or a silicone mat.
In a small bowl, make flax egg by combining the ground flaxseed with water. Stir to combine and set aside for 5 minutes to thicken.
In a large bowl, combine the dry ingredients: oats, oat flour, coconut sugar, baking soda, salt, and cinnamon. Whisk until well combined.
In a medium bowl, combine the wet ingredients: flax egg, melted coconut oil, maple syrup, and vanilla extract. Whisk until well combined
Add the wet to the dry and stir with a spatula or wooden spoon until combined. Fold in the chopped dates and walnuts.
Drop rounded 1.5-2 tablespoons of cookie dough onto the baking sheet. Bake for 11-14 minutes depending on the size of your cookies. Let it cool on the baking pan for 15 minutes. Then transfer cookies to a cooling rack to cool completely. Enjoy!