Preheat the oven to 350F. Coat an 8” cast iron skillet with butter or coconut oil and set aside.
In a small saucepan, heat butter, ½ cup chocolate chips, and cacao powder, stirring occasionally, until melted and smooth.
In a large mixing bowl, beat eggs and coconut sugar on high speed about 3-5 minutes, or until mixture is light in color.
Add melted chocolate mixture slowly, in small amounts at a time, into the bowl of egg mixture while beating on high speed, until all of chocolate mixture is combined with egg mixture.
In a separate bowl, stir together almond meal flour, coconut sugar, arrowroot powder, and salt. Using a spatula, gently fold in dry ingredients into the bowl of wet ingredients, taking care not to overmix. Incorporate just until ingredients are well combined.
Pour brownie batter into prepared skillet and top with remainder of chocolate chips.
Bake in the oven for 16-20 minutes, or until sides begin to pull apart from the skillet and center doesn’t jiggle when skillet is gently moved.
Remove from oven and let cool for 20 minutes.
Enjoy by itself or topped with your favorite vanilla ice cream or homemade whipping cream.