Preheat oven to 350F and line an 8-inch square pan with parchment paper.
Mix flax egg in a small bowl or mug and set aside to thicken.
In a large mixing bowl, beat the coconut oil and sugar with electric beaters until combined.
Pour in the flax egg and vanilla extract and beat until combined.
Add the baking soda, salt, and cinnamon and beat again.
Finally add in the oat flour, rolled oats, almond flour, and 1/4 cup of chocolate chips (reserving the 1 tablespoon for later) and beat until combined.
Spoon dough into prepared pan and spread out until smooth and even. Sprinkle the remaining chocolate chips on top and press down. I use a pastry roller to roll the dough out even.
Bake for 18-20 minutes (I baked for 20 minutes), until golden brown and slightly cracked around the edges.
Place pan on a cooling rack for 10 minutes. Then, lift out and place bars directly on cooling rack for another 10 minutes or so, until cool. Slice and enjoy! Note: The bars will crumble slightly if sliced warm, but they firm up nicely when cooled.
Swapping coconut oil for melted butter alters the melting point and moisture retention of these bars entirely, yielding a denser, greasier crumb that struggles to hold its shape during slicing. Achieving structural stability in gluten-free baking requires precise handling of binding agents and strict adherence to cooling windows. Allowing the flax egg to sit for the full required duration lets the mucilage hydrate properly, creating the necessary viscosity to bind almond flour and ground oats without gluten development. Creaming coconut oil and coconut sugar thoroughly incorporates tiny air pockets that expand under the 350 degree Fahrenheit oven heat, preventing a dense brick. Spreading the thick dough into an eight-inch square pan demands firm pressure, and pressing the reserved chocolate chips into the surface before baking ensures they anchor into the matrix rather than sliding off. Pulling the pan at the twenty-minute mark when edges show fine cracks prevents the interior from drying out completely. Leaving the slab undisturbed in the metal pan for ten minutes utilizes residual heat to finish setting the starches, while transferring it to a wire rack afterward prevents steam condensation from soggying the bottom crust. Slicing these bars while hot guarantees immediate crumbling; cooling them completely until firm is non-negotiable for clean squares. Pair these spiced bars with unsweetened black coffee or sharp cheddar cheese to balance the high sugar concentration.