Prepare the flax egg by mixing 1 tablespoon of ground flax seeds with 3 tablespoons of cold water, then let that mixture chill in the fridge for 10 minutes.
Preheat the oven to 375 degrees Fahrenheit.
In a large mixing bowl, add the melted coconut oil, coconut sugar, maple syrup, flax egg, vanilla extract, salt, and cinnamon, then mix to combine.
Add the gluten-free oat flour and baking soda, then mix to combine.
Use your hands to roll the dough into 12 evenly sized balls, then place them evenly spaced on a baking sheet lined with parchment paper.
Use your fingers to flatten the cookie dough balls into circle shapes.
Bake for 10-12 minutes or until golden brown.
Allow the cookies to cool before removing from the pan and serving.