Preheat your oven to 375 and line a pan with parchment paper.
In a large mixing bowl, stir together your dry ingredients: oats, oat flour, walnuts, chia seeds, baking soda and salt.
In a small mixing bowl, whisk together your wet ingredients: cashew butter, honey, lemon juice, lemon zest, vanilla and egg.
Pour your wet ingredients into your dry ingredients and stir together until everything is well incorporated.
Using a small cookie scoop, scoop your cookie dough onto your pan. Flatten your dough out gently as these cookies don't spread much.
Bake for 9-11 minutes, or till the tops of the cookies are set.
These cookies stay best stored in an airtight container on the counter for about 3 days, or in the fridge for about a week.