Line a 9×9 square pan with parchment paper and set aside. Preheat oven to 350º F.
Add the almond flour, cacao powder, baking soda, and sea salt to a bowl, and stir to combine.
Into a large mixing bowl, whisk eggs, and then whisk in melted coconut oil (or melted butter), coconut sugar, and vanilla.
Add the dry ingredients into the bowl with the wet ingredients, and stir into a smooth batter. Fold in chocolate chips or walnuts, if desired.
Pour the brownie batter into the prepared baking dish. Top with additional chocolate chips, if desired.
Bake the brownies for 18-20 minutes. Allow to fully cool prior to slicing.