Preheat your oven to 350°F and line a 9 x 13" cake pan with parchment paper or aluminum foil. Leave an overhang to make removing from the pan easier.
Sift the almond flour, cocoa powder, and salt in a medium bowl and set aside.
In a large bowl, add the unsalted butter and 3 ounces of the semi-sweet chocolate. Microwave in 15-second intervals, stirring in between, until both are melted and smooth. Add both sugars and whisk well to combine.
Add the eggs and vanilla extract and whisk vigorously until smooth. Mix in the sifted dry ingredients until combined, then stir in the remaining 3 ounces (half a cup) chopped chocolate or chocolate chips.
Pour the batter into the prepared pan and use a spatula to spread it out evenly. Bake in the preheated oven for 30-32 minutes. A toothpick in the center should come out mostly clean when the brownies are done.
Allow the brownies to cool in the pan for at least 1 hour before removing and slicing.