Preheat oven to 350°F. Lightly grease edges and corners of a 9x9-inch baking pan (I use refined coconut oil or regular olive oil for this). Set aside.
In a medium microwave-safe bowl combine 2/3 cup chocolate chips and the coconut oil. Microwave, uncovered, on 30% power (medium-low) for 2 to 3 minutes or until chocolate is melted, stirring twice. Set aside about 5 minutes to cool slightly.
In a large mixing bowl combine sugar and eggs. Beat with an electric mixer on medium to high speed for 2 to 3 minutes or until mixture has lightened in color and is slightly thicker.
Meanwhile, in a medium bowl whisk together flour, cocoa powder, salt, baking powder, and baking soda. Add melted chocolate to bowl with eggs. Beat until well combined. Add flour mixture all at once to egg mixture. Beat on low speed until well combined. If needed, whisk further to remove any lumps.
Stir in 1/3 cup chocolate chips. Spread batter evenly into prepared pan. Bake** for 20 to 22 minutes or until top is evenly puffed and center looks dry and set. Top should barely spring back when you lightly touch the center.
Cool brownies completely in pan on a wire rack before cutting.