Preheat the oven to 350F degrees and adjust the oven rack to the middle position. Line a 6-inch square cake pan with aluminum foil - 2 strips to cover all the sides of the pan. Leave enough overhang to lift the brownies out of the pan. Lightly grease the aluminum foil. Note - The brownies can also be made in a 9x5 inch loaf pan.
In a medium mixing bowl, add the egg, sugar, and vanilla extract. Whisk the mixture very well for a couple of minutes until it is creamy and foamy. This helps create the crinkly and shiny brownie tops. Note - I like to mix the egg and sugar as the first step because it helps to 'dissolve' the coconut sugar. I will even go back and whisk the mix a couple of times while I'm waiting for the chocolate to melt.
Melt the chocolate - In another small mixing bowl, add the chocolate chips, butter, and coconut oil. You can either melt the chocolate over a double boiler (see Notes for details), or in the microwave in 30 second increments - stirring after each - until the chocolate chips are mostly melted. A few small chocolate lumps are ok because they will melt with the residual heat. Set aside and let cool for a couple of minutes - adding too hot of chocolate to the egg mixture and the egg will scramble.
While the chocolate is melting - In a small bowl, whisk together the almond flour, tapioca flour, cocoa powder and salt.
Pour the chocolate mixture into the egg mixture and stir until incorporated. Then sprinkle the dry ingredients over the top of the wet and stir until no dry streaks remain.
Pour the batter into the prepared baking pan and bake the brownies for 23 to 26 minutes, or until a toothpick inserted in the middle comes out mostly clean - we want a few moist crumbs for fudgy brownies.
Cool in the pan set on a wire rack for 15 minutes, then lift the brownies out of the pan and transfer to the wire rack to cool completely. Note - I recommend allowing the brownies to cool completely before slicing and serving. They need time to set and cool to get chewy and fudgy.