Preheat oven to 350 degrees Fahrenheit and spray an 8 by 8 pan with nonstick cooking spray. Make sure there is no flour in your cooking spray.
Put the butter and dark chocolate chips in a large microwave safe bowl and cook for 1 minute. Stir mixture up a bit then microwave again for 30 seconds. Add cocoa powder and stir.
At this point everything should be melty and you can stir it up until the mixture is completely melted and smooth.
Add all of the sugar and stir until well combined.
Next add each egg one at a time and stir only until incorporated. Do not overstir!
Add gluten free all purpose flour, baking powder and salt to mixture and stir until completely mixed together. Stir in semisweet chocolate chips.
Scrape batter with a spatula into the greased 8 by 8 pan and spread evenly with spatula. Bake for 30 minutes until the top is cracked and a toothpick comes out clean. Mine took exactly 30 minutes.