Brown the butter: place the butter in a light colored small saucepan set over medium heat. Cook, as it melts, then begins to sputter and spit. You’ll see tiny panko-like bits at the bottom of the pan. Keep stirring and cooking, the bits will turn an amber brown then a toasty medium brown. Once they are all brown immediately transfer to a medium sized bowl.
While butter is hot, add the ginger and spices (ginger and cinnamon) and stir gently. Let it cool.
Mix the water and ground flax together in a small bowl and let sit for 5 minutes until thickened.
Into the cooled, spiced brown butter mixture add the vanilla, salt, brown sugar and granulated sugar. Whisk for about 30 seconds.
Add the thickened flax to the bowl and whisk until the batter becomes cohesive and thick. Add the molasses and whisk for another 20-30 seconds.
Add the oat flour and baking soda and stir until no streaks of flour remain (the dough will be stiff).
Cover the bowl and leave at room temperature for two hours or chill in the fridge for an hour.
Preheat the oven to 350 F and line 2 cookie sheets with parchment paper.
Use a disher to portion the cookies into 2 tablespoons of dough per cookie. Leave enough space for the cookies to spread - at least a 2 inch diameter around each.
Roll each ball of dough between your palms to smooth it over. The dough will be a lot looser at this stage.
If you like, roll the cookies in a bowl with granulated sugar to coat them.
Bake the cookies until cracked all over and there’s a slight color developing around the edges, for about 12 minutes.
Store leftovers in an airtight container. The cookies are chewier the next day!